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-.\" Copyright (c) 1983, 1995 Eric P. Allman
-.\" Copyright (c) 1983, 1993
-.\"	The Regents of the University of California.  All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\"    notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\"    notice, this list of conditions and the following disclaimer in the
-.\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\"    must display the following acknowledgement:
-.\"	This product includes software developed by the University of
-.\"	California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
-.\"    may be used to endorse or promote products derived from this software
-.\"    without specific prior written permission.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-.\" SUCH DAMAGE.
-.\"
-.\"	@(#)op.me	8.106 (Berkeley) 10/20/97
-.\"
-.\" eqn op.me | pic | troff -me
-.eh 'SMM:08-%''Sendmail Installation and Operation Guide'
-.oh 'Sendmail Installation and Operation Guide''SMM:08-%'
-.\" SD is lib if sendmail is installed in /usr/lib, sbin if in /usr/sbin
-.ds SD sbin
-.\" SB is bin if newaliases/mailq are installed in /usr/bin, ucb if in /usr/ucb
-.ds SB bin
-.nr si 3n
-.de $0
-.(x
-.in \\$3u*3n
-.ti -3n
-\\$2.  \\$1
-.)x
-..
-.de $C
-.(x
-.in 0
-\\$1 \\$2.  \\$3
-.)x
-..
-.sc
-.+c
-.(l C
-.sz 16
-.b SENDMAIL
-.sz 12
-.sp
-.b "INSTALLATION AND OPERATION GUIDE"
-.sz 10
-.sp
-.r
-Eric Allman
-eric@Sendmail.ORG
-.sp
-Version 8.106
-.sp
-For Sendmail Version 8.8
-.)l
-.sp 2
-.pp
-.i Sendmail
-implements a general purpose internetwork mail routing facility
-under the UNIX\(rg
-operating system.
-It is not tied to any one transport protocol \*-
-its function may be likened to a crossbar switch,
-relaying messages from one domain into another.
-In the process,
-it can do a limited amount of message header editing
-to put the message into a format that is appropriate
-for the receiving domain.
-All of this is done under the control of a configuration file.
-.pp
-Due to the requirements of flexibility
-for
-.i sendmail ,
-the configuration file can seem somewhat unapproachable.
-However, there are only a few basic configurations
-for most sites,
-for which standard configuration files have been supplied.
-Most other configurations
-can be built by adjusting an existing configuration files
-incrementally.
-.pp
-.i Sendmail
-is based on
-RFC821 (Simple Mail Transport Protocol),
-RFC822 (Internet Mail Format Protocol),
-RFC1123 (Internet Host Requirements),
-RFC1521 (MIME),
-RFC1651 (SMTP Service Extensions),
-RFC1891 (SMTP Delivery Status Notifications),
-RFC1892 (Multipart/Report),
-RFC1893 (Mail System Status Codes),
-RFC1894 (Delivery Status Notifications),
-and
-RFC1985 (SMTP Service Extension for Remote Message Queue Starting).
-However, since
-.i sendmail
-is designed to work in a wider world,
-in many cases it can be configured to exceed these protocols.
-These cases are described herein.
-.pp
-Although
-.i sendmail
-is intended to run
-without the need for monitoring,
-it has a number of features
-that may be used to monitor or adjust the operation
-under unusual circumstances.
-These features are described.
-.pp
-Section one describes how to do a basic
-.i sendmail
-installation.
-Section two
-explains the day-to-day information you should know
-to maintain your mail system.
-If you have a relatively normal site,
-these two sections should contain sufficient information
-for you to install
-.i sendmail
-and keep it happy.
-Section three
-describes some parameters that may be safely tweaked.
-Section four
-has information regarding the command line arguments.
-Section five
-contains the nitty-gritty information about the configuration
-file.
-This section is for masochists
-and people who must write their own configuration file.
-Section six
-describes configuration that can be done at compile time.
-Section seven
-gives a brief description of differences
-in this version of
-.i sendmail .
-The appendixes give a brief
-but detailed explanation of a number of features
-not described in the rest of the paper.
-.pp
-.b WARNING:
-Several major changes were introduced in version 8.7.
-You should not attempt to use this document
-for prior versions of
-.i sendmail .
-.bp
-.rs
-.sp |4i
-.ce 2
-This page intentionally left blank;
-replace it with a blank sheet for double-sided output.
-.bp 7
-.sh 1 "BASIC INSTALLATION"
-.pp
-There are two basic steps to installing
-.i sendmail .
-The hard part is to build the configuration table.
-This is a file that
-.i sendmail
-reads when it starts up
-that describes the mailers it knows about,
-how to parse addresses,
-how to rewrite the message header,
-and the settings of various options.
-Although the configuration table is quite complex,
-a configuration can usually be built
-by adjusting an existing off-the-shelf configuration.
-The second part is actually doing the installation,
-i.e., creating the necessary files, etc.
-.pp
-The remainder of this section will describe the installation of
-.i sendmail
-assuming you can use one of the existing configurations
-and that the standard installation parameters are acceptable.
-All pathnames and examples
-are given from the root of the
-.i sendmail
-subtree,
-normally
-.i /usr/src/usr.\*(SD/sendmail
-on 4.4BSD.
-.pp
-If you are loading this off the tape,
-continue with the next section.
-If you have a running binary already on your system,
-you should probably skip to section 1.2.
-.sh 2 "Compiling Sendmail"
-.pp
-All
-.i sendmail
-source is in the
-.i src
-subdirectory.
-If you are running on a 4.4BSD system,
-compile by typing
-.q make .
-On other systems, you may have to make some other adjustments.
-On most systems,
-you can do the appropriate compilation by typing
-.(b
-sh makesendmail
-.)b
-This will leave the binary in an appropriately named subdirectory.
-It works for multiple object versions
-compiled out of the same directory.
-.sh 3 "Tweaking the Makefile"
-.pp
-.i Sendmail
-supports two different formats
-for the local (on disk) version of databases,
-notably the
-.i aliases
-database.
-At least one of these should be defined if at all possible.
-.nr ii 1i
-.ip NDBM
-The ``new DBM'' format,
-available on nearly all systems around today.
-This was the preferred format prior to 4.4BSD.
-It allows such complex things as multiple databases
-and closing a currently open database.
-.ip NEWDB
-The new database package from Berkeley.
-If you have this, use it.
-It allows
-long records,
-multiple open databases,
-real in-memory caching,
-and so forth.
-You can define this in conjunction with one of the other two;
-if you do,
-old databases are read,
-but when a new database is created it will be in NEWDB format.
-As a nasty hack,
-if you have NEWDB, NDBM, and NIS defined,
-and if the alias file name includes the substring
-.q /yp/ ,
-.i sendmail
-will create both new and old versions of the alias file
-during a
-.i newalias
-command.
-This is required because the Sun NIS/YP system
-reads the DBM version of the alias file.
-It's ugly as sin,
-but it works.
-.lp
-If neither of these are defined,
-.i sendmail
-reads the alias file into memory on every invocation.
-This can be slow and should be avoided.
-There are also several methods for remote database access:
-.ip NIS
-Sun's Network Information Services (formerly YP).
-.ip NISPLUS
-Sun's NIS+ services.
-.ip NETINFO
-NeXT's NetInfo service.
-.ip HESIOD
-Hesiod service (from Athena).
-.lp
-Other compilation flags are set in conf.h
-and should be predefined for you
-unless you are porting to a new environment.
-.sh 3 "Compilation and installation"
-.pp
-After making the local system configuration described above,
-You should be able to compile and install the system.
-The script
-.q makesendmail
-is the best approach on most systems:
-.(b
-sh makesendmail
-.)b
-This will use
-.i uname (1)
-to select the correct Makefile for your environment.
-.pp
-You may be able to install using
-.(b
-sh makesendmail install
-.)b
-This should install the binary in
-/usr/\*(SD
-and create links from
-/usr/\*(SB/newaliases
-and
-/usr/\*(SB/mailq
-to
-/usr/\*(SD/sendmail.
-On 4.4BSD systems it will also format and install man pages.
-.sh 2 "Configuration Files"
-.pp
-.i Sendmail
-cannot operate without a configuration file.
-The configuration defines the mail delivery mechanisms understood at this site,
-how to access them,
-how to forward email to remote mail systems,
-and a number of tuning parameters.
-This configuration file is detailed
-in the later portion of this document.
-.pp
-The
-.i sendmail
-configuration can be daunting at first.
-The world is complex,
-and the mail configuration reflects that.
-The distribution includes an m4-based configuration package
-that hides a lot of the complexity.
-.pp
-These configuration files are simpler than old versions
-largely because the world has become simpler;
-in particular,
-text-based host files are officially eliminated,
-obviating the need to
-.q hide
-hosts behind a registered internet gateway.
-.pp
-These files also assume that most of your neighbors
-use domain-based UUCP addressing;
-that is,
-instead of naming hosts as
-.q host!user
-they will use
-.q host.domain!user .
-The configuration files can be customized to work around this,
-but it is more complex.
-.pp
-Our configuration files are processed by
-.i m4
-to facilitate local customization;
-the directory
-.i cf
-of the
-.i sendmail
-distribution directory
-contains the source files.
-This directory contains several subdirectories:
-.nr ii 1i
-.ip cf
-Both site-dependent and site-independent descriptions of hosts.
-These can be literal host names
-(e.g.,
-.q ucbvax.mc )
-when the hosts are gateways
-or more general descriptions
-(such as
-.q "tcpproto.mc"
-as a general description of an SMTP-connected host
-or
-.q "uucpproto.mc"
-as a general description of a UUCP-connected host).
-Files ending
-.b \&.mc
-(``Master Configuration'')
-are the input descriptions;
-the output is in the corresponding
-.b \&.cf
-file.
-The general structure of these files is described below.
-.ip domain
-Site-dependent subdomain descriptions.
-These are tied to the way your organization wants to do addressing.
-For example,
-.b domain/cs.exposed.m4
-is our description for hosts in the CS.Berkeley.EDU subdomain
-that want their individual hostname to be externally visible;
-.b domain/cs.hidden.m4
-is the same except that the hostname is hidden
-(everything looks like it comes from CS.Berkeley.EDU).
-These are referenced using the
-.sm DOMAIN
-.b m4
-macro in the
-.b \&.mc
-file.
-.ip feature
-Definitions of specific features that some particular host in your site
-might want.
-These are referenced using the
-.sm FEATURE
-.b m4
-macro.
-An example feature is
-use_cw_file
-(which tells
-.i sendmail
-to read an /etc/sendmail.cw file on startup
-to find the set of local names).
-.ip hack
-Local hacks, referenced using the
-.sm HACK
-.b m4
-macro.
-Try to avoid these.
-The point of having them here is to make it clear that they smell.
-.ip m4
-Site-independent
-.i m4 (1)
-include files that have information common to all configuration files.
-This can be thought of as a
-.q #include
-directory.
-.ip mailer
-Definitions of mailers,
-referenced using the
-.sm MAILER
-.b m4
-macro.
-The mailer types that are known in this distribution are
-fax,
-local,
-smtp,
-uucp,
-and usenet.
-For example, to include support for the UUCP-based mailers,
-use
-.q MAILER(uucp) .
-.ip ostype
-Definitions describing various operating system environments
-(such as the location of support files).
-These are referenced using the
-.sm OSTYPE
-.b m4
-macro.
-.ip sh
-Shell files used by the
-.b m4
-build process.
-You shouldn't have to mess with these.
-.ip siteconfig
-Local UUCP connectivity information.
-They normally contain lists of site information, for example:
-.(b
-SITE(contessa)
-SITE(hoptoad)
-SITE(nkainc)
-SITE(well)
-.)b
-They are referenced using the SITECONFIG macro:
-.(b
-SITECONFIG(site.config.file, name_of_site, X)
-.)b
-where
-.i X
-is the macro/class name to use.
-It can be U
-(indicating locally connected hosts)
-or one of W, X, or Y
-for up to three remote UUCP hubs.
-This directory has been supplanted by the mailertable feature;
-any new configurations should use that feature to do UUCP
-(and other) routing.
-.pp
-If you are in a new domain
-(e.g., a company),
-you will probably want to create a
-cf/domain
-file for your domain.
-This consists primarily of relay definitions:
-for example, Berkeley's domain definition
-defines relays for
-BitNET,
-CSNET,
-and UUCP.
-Of these,
-only the UUCP relay is particularly specific
-to Berkeley.
-All of these are internet-style domain names.
-Please check to make certain they are reasonable for your domain.
-.pp
-Subdomains at Berkeley are also represented in the
-cf/domain
-directory.
-For example,
-the domain
-cs-exposed
-is the Computer Science subdomain with the local hostname shown
-to other users;
-cs-hidden
-makes users appear to be from the CS.Berkeley.EDU subdomain
-(with no local host information included).
-You will probably have to update this directory
-to be appropriate for your domain.
-.pp
-You will have to use or create
-.b \&.mc
-files in the
-.i cf/cf
-subdirectory for your hosts.
-This is detailed in the
-cf/README
-file.
-.sh 2 "Details of Installation Files"
-.pp
-This subsection describes the files that
-comprise the
-.i sendmail
-installation.
-.sh 3 "/usr/\*(SD/sendmail"
-.pp
-The binary for
-.i sendmail
-is located in /usr/\*(SD\**.
-.(f
-\**This is usually
-/usr/sbin
-on 4.4BSD and newer systems;
-many systems install it in
-/usr/lib.
-I understand it is in /usr/ucblib
-on System V Release 4.
-.)f
-It should be setuid root.
-For security reasons,
-/, /usr, and /usr/\*(SD
-should be owned by root, mode 755\**.
-.(f
-\**Some vendors ship them owned by bin;
-this creates a security hole that is not actually related to
-.i sendmail .
-Other important directories that should have restrictive ownerships
-and permissions are
-/bin, /usr/bin, /etc, /usr/etc, /lib, and /usr/lib.
-.)f
-.sh 3 "/etc/sendmail.cf"
-.pp
-This is the configuration file for
-.i sendmail \**.
-.(f
-\**Actually, the pathname varies depending on the operating system;
-/etc is the preferred directory.
-Some older systems install it in
-.b /usr/lib/sendmail.cf ,
-and I've also seen it in
-.b /usr/ucblib
-and
-.b /etc/mail .
-If you want to move this file,
-change
-.i src/conf.h .
-.)f
-This and /etc/sendmail.pid
-are the only non-library file names compiled into
-.i sendmail \**.
-.(f
-\**The system libraries can reference other files;
-in particular, system library subroutines that
-.i sendmail
-calls probably reference
-.i /etc/passwd
-and
-.i /etc/resolv.conf .
-.)f
-.pp
-The configuration file is normally created
-using the distribution files described above.
-If you have a particularly unusual system configuration
-you may need to create a special version.
-The format of this file is detailed in later sections
-of this document.
-.sh 3 "/usr/\*(SB/newaliases"
-.pp
-The
-.i newaliases
-command should just be a link to
-.i sendmail :
-.(b
-rm \-f /usr/\*(SB/newaliases
-ln \-s /usr/\*(SD/sendmail /usr/\*(SB/newaliases
-.)b
-This can be installed in whatever search path you prefer
-for your system.
-.sh 3 "/usr/\*(SB/hoststat"
-.pp
-The
-.i hoststat
-command should just be a link to 
-.i sendmail ,
-in a fashion similar to
-.i newaliases .
-This command lists the status of the last mail transaction
-with all remote hosts.
-It functions only when the
-.b HostStatusDirectory
-option is set.
-.sh 3 "/usr/\*(SB/purgestat"
-.pp
-This command is also a link to
-.i sendmail .
-It flushes all information that is stored in the
-.b HostStatusDirectory
-tree.
-.sh 3 "/var/spool/mqueue"
-.pp
-The directory
-.i /var/spool/mqueue
-should be created to hold the mail queue.
-This directory should be mode 700
-and owned by root.
-.pp
-The actual path of this directory
-is defined in the
-.b Q
-option of the
-.i sendmail.cf
-file.
-.sh 3 "/var/spool/mqueue/.hoststat"
-.pp
-This is a typical value for the
-.b HostStatusDirectory
-option,
-containing one file per host
-that this sendmail has chatted with recently.
-It is normally a subdirectory of
-.i mqueue .
-.sh 3 "/etc/aliases*"
-.pp
-The system aliases are held in
-.q /etc/aliases .
-A sample is given in
-.q lib/aliases
-which includes some aliases which
-.i must
-be defined:
-.(b
-cp lib/aliases /etc/aliases
-.i "edit /etc/aliases"
-.)b
-You should extend this file with any aliases that are apropos to your system.
-.pp
-Normally
-.i sendmail
-looks at a version of these files maintained by the
-.i dbm \|(3)
-or
-.i db \|(3)
-routines.
-These are stored either in
-.q /etc/aliases.dir
-and
-.q /etc/aliases.pag
-or
-.q /etc/aliases.db
-depending on which database package you are using.
-These can initially be created as empty files,
-but they will have to be initialized promptly.
-These should be mode 644:
-.(b
-cp /dev/null /etc/aliases.dir
-cp /dev/null /etc/aliases.pag
-chmod 644 /etc/aliases.*
-newaliases
-.)b
-The
-.i db
-routines preset the mode reasonably,
-so this step can be skipped.
-The actual path of this file
-is defined in the
-.b AliasFile
-option of the
-.i sendmail.cf
-file.
-.sh 3 "/etc/rc"
-.pp
-It will be necessary to start up the
-.i sendmail
-daemon when your system reboots.
-This daemon performs two functions:
-it listens on the SMTP socket for connections
-(to receive mail from a remote system)
-and it processes the queue periodically
-to insure that mail gets delivered when hosts come up.
-.pp
-Add the following lines to
-.q /etc/rc
-(or
-.q /etc/rc.local
-as appropriate)
-in the area where it is starting up the daemons:
-.(b
-if [ \-f /usr/\*(SD/sendmail \-a \-f /etc/sendmail.cf ]; then
-	(cd /var/spool/mqueue; rm \-f [lnx]f*)
-	/usr/\*(SD/sendmail \-bd \-q30m &
-	echo \-n ' sendmail' >/dev/console
-fi
-.)b
-The
-.q cd
-and
-.q rm
-commands insure that all lock files have been removed;
-extraneous lock files may be left around
-if the system goes down in the middle of processing a message.
-The line that actually invokes
-.i sendmail
-has two flags:
-.q \-bd
-causes it to listen on the SMTP port,
-and
-.q \-q30m
-causes it to run the queue every half hour.
-.pp
-Some people use a more complex startup script,
-removing zero length qf files and df files for which there is no qf file.
-For example, see Figure 1
-for an example of a complex startup script.
-.(z
-.hl
-# remove zero length qf files
-for qffile in qf*
-do
-	if [ \-r $qffile ]
-	then
-		if [ ! \-s $qffile ]
-		then
-			echo \-n " <zero: $qffile>" > /dev/console
-			rm \-f $qffile
-		fi
-	fi
-done
-# rename tf files to be qf if the qf does not exist
-for tffile in tf*
-do
-	qffile=`echo $tffile | sed 's/t/q/'`
-	if [ \-r $tffile \-a ! \-f $qffile ]
-	then
-		echo \-n " <recovering: $tffile>" > /dev/console
-		mv $tffile $qffile
-	else
-		echo \-n " <extra: $tffile>" > /dev/console
-		rm \-f $tffile
-	fi
-done
-# remove df files with no corresponding qf files
-for dffile in df*
-do
-	qffile=`echo $dffile | sed 's/d/q/'`
-	if [ \-r $dffile \-a ! \-f $qffile ]
-	then
-		echo \-n " <incomplete: $dffile>" > /dev/console
-		mv $dffile `echo $dffile | sed 's/d/D/'`
-	fi
-done
-# announce files that have been saved during disaster recovery
-for xffile in [A-Z]f*
-do
-	echo \-n " <panic: $xffile>" > /dev/console
-done
-.sp
-.ce
-Figure 1 \(em A complex startup script
-.hl
-.)z
-.pp
-If you are not running a version of UNIX
-that supports Berkeley TCP/IP,
-do not include the
-.b \-bd
-flag.
-.sh 3 "/usr/lib/sendmail.hf"
-.pp
-This is the help file used by the SMTP
-.b HELP
-command.
-It should be copied from
-.q lib/sendmail.hf :
-.(b
-cp lib/sendmail.hf /usr/lib
-.)b
-The actual path of this file
-is defined in the
-.b H
-option of the
-.i sendmail.cf
-file.
-.sh 3 "/etc/sendmail.st"
-.pp
-If you wish to collect statistics
-about your mail traffic,
-you should create the file
-.q /etc/sendmail.st :
-.(b
-cp /dev/null /etc/sendmail.st
-chmod 666 /etc/sendmail.st
-.)b
-This file does not grow.
-It is printed with the program
-.q mailstats/mailstats.c.
-The actual path of this file
-is defined in the
-.b S
-option of the
-.i sendmail.cf
-file.
-.sh 3 "/usr/\*(SB/mailq"
-.pp
-If
-.i sendmail
-is invoked as
-.q mailq,
-it will simulate the
-.b \-bp
-flag
-(i.e.,
-.i sendmail
-will print the contents of the mail queue;
-see below).
-This should be a link to /usr/\*(SD/sendmail.
-.sh 1 "NORMAL OPERATIONS"
-.sh 2 "The System Log"
-.pp
-The system log is supported by the
-.i syslogd \|(8)
-program.
-All messages from
-.i sendmail
-are logged under the
-.sm LOG_MAIL
-facility\**.
-.(f
-\**Except on Ultrix,
-which does not support facilities in the syslog.
-.)f
-.sh 3 "Format"
-.pp
-Each line in the system log
-consists of a timestamp,
-the name of the machine that generated it
-(for logging from several machines
-over the local area network),
-the word
-.q sendmail: ,
-and a message\**.
-.(f
-\**This format may vary slightly if your vendor has changed
-the syntax.
-.)f
-Most messages are a sequence of
-.i name \c
-=\c
-.i value
-pairs.
-.pp
-The two most common lines are logged when a message is processed.
-The first logs the receipt of a message;
-there will be exactly one of these per message.
-Some fields may be omitted if they do not contain interesting information.
-Fields are:
-.ip from
-The envelope sender address.
-.ip size
-The size of the message in bytes.
-.ip class
-The class (i.e., numeric precedence) of the message.
-.ip pri
-The initial message priority (used for queue sorting).
-.ip nrcpts
-The number of envelope recipients for this message
-(after aliasing and forwarding).
-.ip msgid
-The message id of the message (from the header).
-.ip proto
-The protocol used to receive this message (e.g., ESMTP or UUCP)
-.ip relay
-The machine from which it was received.
-.lp
-There is also one line logged per delivery attempt
-(so there can be several per message if delivery is deferred
-or there are multiple recipients).
-Fields are:
-.ip to
-A comma-separated list of the recipients to this mailer.
-.ip ctladdr
-The ``controlling user'', that is, the name of the user
-whose credentials we use for delivery.
-.ip delay
-The total delay between the time this message was received
-and the time it was delivered.
-.ip xdelay
-The amount of time needed in this delivery attempt
-(normally indicative of the speed of the connection).
-.ip mailer
-The name of the mailer used to deliver to this recipient.
-.ip relay
-The name of the host that actually accepted (or rejected) this recipient.
-.ip stat
-The delivery status.
-.lp
-Not all fields are present in all messages;
-for example, the relay is not listed for local deliveries.
-.sh 3 "Levels"
-.pp
-If you have
-.i syslogd \|(8)
-or an equivalent installed,
-you will be able to do logging.
-There is a large amount of information that can be logged.
-The log is arranged as a succession of levels.
-At the lowest level
-only extremely strange situations are logged.
-At the highest level,
-even the most mundane and uninteresting events
-are recorded for posterity.
-As a convention,
-log levels under ten
-are considered generally
-.q useful;
-log levels above 64
-are reserved for debugging purposes.
-Levels from 11\-64 are reserved for verbose information
-that some sites might want.
-.pp
-A complete description of the log levels
-is given in section
-.\" XREF
-4.6.
-.sh 2 "Dumping State"
-.pp
-You can ask
-.i sendmail
-to log a dump of the open files
-and the connection cache
-by sending it a
-.sm SIGUSR1
-signal.
-The results are logged at
-.sm LOG_DEBUG
-priority.
-.sh 2 "The Mail Queue"
-.pp
-Sometimes a host cannot handle a message immediately.
-For example, it may be down or overloaded, causing it to refuse connections.
-The sending host is then expected to save this message in
-its mail queue
-and attempt to deliver it later.
-.pp
-Under normal conditions the mail queue will be processed transparently.
-However, you may find that manual intervention is sometimes necessary.
-For example,
-if a major host is down for a period of time
-the queue may become clogged.
-Although
-.i sendmail
-ought to recover gracefully when the host comes up,
-you may find performance unacceptably bad in the meantime.
-.sh 3 "Printing the queue"
-.pp
-The contents of the queue can be printed
-using the
-.i mailq
-command
-(or by specifying the
-.b \-bp
-flag to
-.i sendmail ):
-.(b
-mailq
-.)b
-This will produce a listing of the queue id's,
-the size of the message,
-the date the message entered the queue,
-and the sender and recipients.
-.sh 3 "Forcing the queue"
-.pp
-.i Sendmail
-should run the queue automatically
-at intervals.
-The algorithm is to read and sort the queue,
-and then to attempt to process all jobs in order.
-When it attempts to run the job,
-.i sendmail
-first checks to see if the job is locked.
-If so, it ignores the job.
-.pp
-There is no attempt to insure that only one queue processor
-exists at any time,
-since there is no guarantee that a job cannot take forever
-to process
-(however,
-.i sendmail
-does include heuristics to try to abort jobs
-that are taking absurd amounts of time;
-technically, this violates RFC 821, but is blessed by RFC 1123).
-Due to the locking algorithm,
-it is impossible for one job to freeze the entire queue.
-However,
-an uncooperative recipient host
-or a program recipient
-that never returns
-can accumulate many processes in your system.
-Unfortunately,
-there is no completely general way to solve this.
-.pp
-In some cases,
-you may find that a major host going down
-for a couple of days
-may create a prohibitively large queue.
-This will result in
-.i sendmail
-spending an inordinate amount of time
-sorting the queue.
-This situation can be fixed by moving the queue to a temporary place
-and creating a new queue.
-The old queue can be run later when the offending host returns to service.
-.pp
-To do this,
-it is acceptable to move the entire queue directory:
-.(b
-cd /var/spool
-mv mqueue omqueue; mkdir mqueue; chmod 700 mqueue
-.)b
-You should then kill the existing daemon
-(since it will still be processing in the old queue directory)
-and create a new daemon.
-.pp
-To run the old mail queue,
-run the following command:
-.(b
-/usr/\*(SD/sendmail \-oQ/var/spool/omqueue \-q
-.)b
-The
-.b \-oQ
-flag specifies an alternate queue directory
-and the
-.b \-q
-flag says to just run every job in the queue.
-If you have a tendency toward voyeurism,
-you can use the
-.b \-v
-flag to watch what is going on.
-.pp
-When the queue is finally emptied,
-you can remove the directory:
-.(b
-rmdir /var/spool/omqueue
-.)b
-.sh 2 "Disk Based Connection Information"
-.pp
-.i Sendmail
-stores a large amount of information about each remote system it
-has connected to in memory. It is now possible to preserve some 
-of this information on disk as well, by using the
-.b HostStatusDirectory
-option, so that it may be shared between several invocations of
-.i sendmail .
-This allows mail to be queued immediately or skipped during a queue run if
-there has been a recent failure in connecting to a remote machine. 
-.pp
-Additionally enabling
-.b SingleThreadDelivery
-has the added effect of single-threading mail delivery to a destination.
-This can be quite helpful
-if the remote machine is running an SMTP server that is easily overloaded
-or cannot accept more than a single connection at a time,
-but can cause some messages to be punted to a future queue run.
-It also applies to
-.i all
-hosts, so setting this because you have one machine on site
-that runs some software that is easily overrun
-can cause mail to other hosts to be slowed down.
-If this option is set,
-you probably want to set the
-.b MinQueueAge
-option as well and run the queue fairly frequently;
-this will cause hosts that are skipped because another
-.i sendmail
-instance is talking to it to be tried again soon.
-.pp
-The disk based host information is stored in a subdirectory of of the 
-.b mqueue
-directory called
-.b \&.hoststat \**.
-.(f
-\**This is the usual value of the
-.b HostStatusDirectory
-option;
-it can, of course, go anywhere you like in your filesystem.
-.)f
-Removing this directory and its subdirectories has an effect similar to
-the 
-.i purgestat
-command and is completely safe.
-The information in these directories can
-be perused with the
-.i hoststat
-command, which will indicate the host name, the last access, and the
-status of that access.
-An asterisk in the left most column indicates that a
-.i sendmail
-process currently has the host locked for mail delivery.
-.pp
-The disk based connection information is treated the same way as memory based 
-connection information for the purpose of timeouts.
-By default, information about host failures is valid for 30 minutes.
-This can be adjusted with
-the
-.b Timeout.hoststatus
-option.
-.pp
-The connection information stored on disk may be purged at any time
-with the 
-.i purgestat
-command or by invoking sendmail with the 
-.b \-bH
-switch.
-The connection information may be viewed with the
-.i hoststat
-command or by invoking sendmail with the
-.b \-bh
-switch.
-.sh 2 "The Service Switch"
-.pp
-The implementation of certain system services
-such as host and user name lookup
-is controlled by the service switch.
-If the host operating system supports such a switch
-.i sendmail
-will use the native version.
-Ultrix, Solaris, and DEC OSF/1 are examples of such systems.
-.pp
-If the underlying operating system does not support a service switch
-(e.g., SunOS, HP-UX, BSD)
-then
-.i sendmail
-will provide a stub implementation.
-The
-.b ServiceSwitchFile
-option points to the name of a file that has the service definitions
-Each line has the name of a service
-and the possible implementations of that service.
-For example, the file:
-.(b
-hosts	dns files nis
-aliases	files nis
-.)b
-will ask
-.i sendmail
-to look for hosts in the Domain Name System first.
-If the requested host name is not found,
-it tries local files,
-and if that fails it tries NIS.
-Similarly,
-when looking for aliases
-it will try the local files first
-followed by NIS.
-.pp
-Service switches are not completely integrated.
-For example, despite the fact that the host entry listed in the above example
-specifies to look in NIS,
-on SunOS this won't happen because the system implementation of
-.i gethostbyname \|(3)
-doesn't understand this.
-If there is enough demand
-.i sendmail
-may reimplement
-.i gethostbyname \|(3),
-.i gethostbyaddr \|(3),
-.i getpwent \|(3),
-and the other system routines that would be necessary
-to make this work seamlessly.
-.sh 2 "The Alias Database"
-.pp
-After recipient addresses are read from the SMTP connection
-or command line
-they are parsed by ruleset 0,
-which must resolve to a
-{\c
-.i mailer ,
-.i host ,
-.i user }
-triple.
-If the flags selected by the
-.i mailer
-includes the
-.b A
-(aliasable) flag,
-the
-.i user
-part of the triple is looked up as the key
-(i.e., the left hand side)
-into the alias database
-If there is a match, the address is deleted from the send queue
-and all addresses on the right hand side of the alias
-are added in place of the alias that was found.
-This is a recursive operation,
-so aliases found in the right hand side of the alias
-are similarly expanded.
-.pp
-The alias database exists in two forms.
-One is a text form,
-maintained in the file
-.i /etc/aliases.
-The aliases are of the form
-.(b
-name: name1, name2, ...
-.)b
-Only local names may be aliased;
-e.g.,
-.(b
-eric@prep.ai.MIT.EDU: eric@CS.Berkeley.EDU
-.)b
-will not have the desired effect
-(except on prep.ai.MIT.EDU,
-and they probably don't want me)\**.
-.(f
-\**Actually, any mailer that has the `A' mailer flag set
-will permit aliasing;
-this is normally limited to the local mailer.
-.)f
-Aliases may be continued by starting any continuation lines
-with a space or a tab.
-Blank lines and lines beginning with a sharp sign
-(\c
-.q # )
-are comments.
-.pp
-The second form is processed by the
-.i ndbm \|(3)\**
-.(f
-\**The
-.i gdbm
-package probably works as well.
-.)f
-or
-.i db \|(3)
-library.
-This form is in the files
-.i /etc/aliases.dir
-and
-.i /etc/aliases.pag.
-This is the form that
-.i sendmail
-actually uses to resolve aliases.
-This technique is used to improve performance.
-.pp
-The control of search order is actually set by the service switch.
-Essentially, the entry
-.(b
-OAswitch:aliases
-.)b
-is always added as the first alias entry;
-also, the first alias file name without a class
-(e.g., without
-.q nis:
-on the front)
-will be used as the name of the file for a ``files'' entry
-in the aliases switch.
-For example, if the configuration file contains
-.(b
-OA/etc/aliases
-.)b
-and the service switch contains
-.(b
-aliases	nis files nisplus
-.)b
-then aliases will first be searched in the NIS database,
-then in /etc/aliases,
-then in the NIS+ database.
-.pp
-You can also use
-.sm NIS -based
-alias files.
-For example, the specification:
-.(b
-OA/etc/aliases
-OAnis:mail.aliases@my.nis.domain
-.)b
-will first search the /etc/aliases file
-and then the map named
-.q mail.aliases
-in
-.q my.nis.domain .
-Warning: if you build your own
-.sm NIS -based
-alias files,
-be sure to provide the
-.b \-l
-flag to
-.i makedbm (8)
-to map upper case letters in the keys to lower case;
-otherwise, aliases with upper case letters in their names
-won't match incoming addresses.
-.pp
-Additional flags can be added after the colon
-exactly like a
-.b K
-line \(em for example:
-.(b
-OAnis:\-N mail.aliases@my.nis.domain
-.)b
-will search the appropriate NIS map and always include null bytes in the key.
-.sh 3 "Rebuilding the alias database"
-.pp
-The DB or DBM version of the database
-may be rebuilt explicitly by executing the command
-.(b
-newaliases
-.)b
-This is equivalent to giving
-.i sendmail
-the
-.b \-bi
-flag:
-.(b
-/usr/\*(SD/sendmail \-bi
-.)b
-.pp
-If the
-.b RebuildAliases
-(old
-.b D )
-option is specified in the configuration,
-.i sendmail
-will rebuild the alias database automatically
-if possible
-when it is out of date.
-Auto-rebuild can be dangerous
-on heavily loaded machines
-with large alias files;
-if it might take more than the rebuild timeout
-(option
-.b AliasWait ,
-old
-.b a ,
-which is normally five minutes)
-to rebuild the database,
-there is a chance that several processes will start the rebuild process
-simultaneously.
-.pp
-If you have multiple aliases databases specified,
-the
-.b \-bi
-flag rebuilds all the database types it understands
-(for example, it can rebuild NDBM databases but not NIS databases).
-.sh 3 "Potential problems"
-.pp
-There are a number of problems that can occur
-with the alias database.
-They all result from a
-.i sendmail
-process accessing the DBM version
-while it is only partially built.
-This can happen under two circumstances:
-One process accesses the database
-while another process is rebuilding it,
-or the process rebuilding the database dies
-(due to being killed or a system crash)
-before completing the rebuild.
-.pp
-Sendmail has three techniques to try to relieve these problems.
-First, it ignores interrupts while rebuilding the database;
-this avoids the problem of someone aborting the process
-leaving a partially rebuilt database.
-Second,
-it locks the database source file during the rebuild \(em
-but that may not work over NFS or if the file is unwritable.
-Third,
-at the end of the rebuild
-it adds an alias of the form
-.(b
-@: @
-.)b
-(which is not normally legal).
-Before
-.i sendmail
-will access the database,
-it checks to insure that this entry exists\**.
-.(f
-\**The
-.b AliasWait
-option is required in the configuration
-for this action to occur.
-This should normally be specified.
-.)f
-.sh 3 "List owners"
-.pp
-If an error occurs on sending to a certain address,
-say
-.q \fIx\fP ,
-.i sendmail
-will look for an alias
-of the form
-.q owner-\fIx\fP
-to receive the errors.
-This is typically useful
-for a mailing list
-where the submitter of the list
-has no control over the maintenance of the list itself;
-in this case the list maintainer would be the owner of the list.
-For example:
-.(b
-unix-wizards: eric@ucbarpa, wnj@monet, nosuchuser,
-	sam@matisse
-owner-unix-wizards: unix-wizards-request
-unix-wizards-request: eric@ucbarpa
-.)b
-would cause
-.q eric@ucbarpa
-to get the error that will occur
-when someone sends to
-unix-wizards
-due to the inclusion of
-.q nosuchuser
-on the list.
-.pp
-List owners also cause the envelope sender address to be modified.
-The contents of the owner alias are used if they point to a single user,
-otherwise the name of the alias itself is used.
-For this reason, and to obey Internet conventions,
-the
-.q owner-
-address normally points at the
-.q -request
-address; this causes messages to go out with the typical Internet convention
-of using ``\c
-.i list -request''
-as the return address.
-.sh 2 "User Information Database"
-.pp
-If you have a version of
-.i sendmail
-with the user information database
-compiled in,
-and you have specified one or more databases using the
-.b U
-option,
-the databases will be searched for a
-.i user :maildrop
-entry.
-If found, the mail will be sent to the specified address.
-.sh 2 "Per-User Forwarding (.forward Files)"
-.pp
-As an alternative to the alias database,
-any user may put a file with the name
-.q .forward
-in his or her home directory.
-If this file exists,
-.i sendmail
-redirects mail for that user
-to the list of addresses listed in the .forward file.
-For example, if the home directory for user
-.q mckusick
-has a .forward file with contents:
-.(b
-mckusick@ernie
-kirk@calder
-.)b
-then any mail arriving for
-.q mckusick
-will be redirected to the specified accounts.
-.pp
-Actually, the configuration file defines a sequence of filenames to check.
-By default, this is the user's .forward file,
-but can be defined to be more generally using the
-.b J
-option.
-If you change this,
-you will have to inform your user base of the change;
-\&.forward is pretty well incorporated into the collective subconscious.
-.sh 2 "Special Header Lines"
-.pp
-Several header lines have special interpretations
-defined by the configuration file.
-Others have interpretations built into
-.i sendmail
-that cannot be changed without changing the code.
-These builtins are described here.
-.sh 3 "Errors-To:"
-.pp
-If errors occur anywhere during processing,
-this header will cause error messages to go to
-the listed addresses.
-This is intended for mailing lists.
-.pp
-The Errors-To: header was created in the bad old days
-when UUCP didn't understand the distinction between an envelope and a header;
-this was a hack to provide what should now be passed
-as the envelope sender address.
-It should go away.
-It is only used if the
-.b UseErrorsTo
-option is set.
-.pp
-The Errors-To: header is official deprecated
-and will go away in a future release.
-.sh 3 "Apparently-To:"
-.pp
-RFC 822 requires at least one recipient field
-(To:, Cc:, or Bcc: line)
-in every message.
-If a message comes in with no recipients listed in the message
-then
-.i sendmail
-will adjust the header based on the
-.q NoRecipientAction
-option.
-One of the possible actions is to add an
-.q "Apparently-To:"
-header line for any recipients it is aware of.
-This is not put in as a standard recipient line
-to warn any recipients that the list is not complete.
-.pp
-The Apparently-To: header is non-standard
-and is deprecated.
-.sh 3 "Precedence"
-.pp
-The Precedence: header can be used as a crude control of message priority.
-It tweaks the sort order in the queue
-and can be configured to change the message timeout values.
-.sh 2 "IDENT Protocol Support"
-.pp
-.i Sendmail
-supports the IDENT protocol as defined in RFC 1413.
-Although this enhances identification
-of the author of an email message
-by doing a ``call back'' to the originating system to include
-the owner of a particular TCP connection
-in the audit trail
-it is in no sense perfect;
-a determined forger can easily spoof the IDENT protocol.
-The following description is excerpted from RFC 1413:
-.ba +5
-.lp
-6.  Security Considerations
-.lp
-The information returned by this protocol is at most as trustworthy
-as the host providing it OR the organization operating the host.  For
-example, a PC in an open lab has few if any controls on it to prevent
-a user from having this protocol return any identifier the user
-wants.  Likewise, if the host has been compromised the information
-returned may be completely erroneous and misleading.
-.lp
-The Identification Protocol is not intended as an authorization or
-access control protocol.  At best, it provides some additional
-auditing information with respect to TCP connections.  At worst, it
-can provide misleading, incorrect, or maliciously incorrect
-information.
-.lp
-The use of the information returned by this protocol for other than
-auditing is strongly discouraged.  Specifically, using Identification
-Protocol information to make access control decisions - either as the
-primary method (i.e., no other checks) or as an adjunct to other
-methods may result in a weakening of normal host security.
-.lp
-An Identification server may reveal information about users,
-entities, objects or processes which might normally be considered
-private.  An Identification server provides service which is a rough
-analog of the CallerID services provided by some phone companies and
-many of the same privacy considerations and arguments that apply to
-the CallerID service apply to Identification.  If you wouldn't run a
-"finger" server due to privacy considerations you may not want to run
-this protocol.
-.ba
-.lp
-In some cases your system may not work properly with IDENT support
-due to a bug in the TCP/IP implementation.
-The symptoms will be that for some hosts
-the SMTP connection will be closed
-almost immediately.
-If this is true or if you do not want to use IDENT,
-you should set the IDENT timeout to zero;
-this will disable the IDENT protocol.
-.sh 1 "ARGUMENTS"
-.pp
-The complete list of arguments to
-.i sendmail
-is described in detail in Appendix A.
-Some important arguments are described here.
-.sh 2 "Queue Interval"
-.pp
-The amount of time between forking a process
-to run through the queue
-is defined by the
-.b \-q
-flag.
-If you run with delivery mode set to
-.b i
-or
-.b b
-this can be relatively large,
-since it will only be relevant
-when a host that was down comes back up.
-If you run in
-.b q
-mode
-it should be relatively short,
-since it defines the maximum amount of time that a message
-may sit in the queue.
-(See also the MinQueueAge option.)
-.pp
-RFC 1123 section 5.3.1.1 says that this value should be at least 30 minutes
-(although that probably doesn't make sense if you use ``queue-only'' mode).
-.sh 2 "Daemon Mode"
-.pp
-If you allow incoming mail over an IPC connection,
-you should have a daemon running.
-This should be set by your
-.i /etc/rc
-file using the
-.b \-bd
-flag.
-The
-.b \-bd
-flag and the
-.b \-q
-flag may be combined in one call:
-.(b
-/usr/\*(SD/sendmail \-bd \-q30m
-.)b
-.pp
-An alternative approach is to invoke sendmail from
-.i inetd (8)
-(use the
-.b \-bs
-flag to ask sendmail to speak SMTP on its standard input and output).
-This works and allows you to wrap
-.i sendmail
-in a TCP wrapper program,
-but may be a bit slower since the configuration file
-has to be re-read on every message that comes in.
-If you do this, you still need to have a
-.i sendmail
-running to flush the queue:
-.(b
-/usr/\*(SD/sendmail \-q30m
-.)b
-.sh 2 "Forcing the Queue"
-.pp
-In some cases you may find that the queue has gotten clogged for some reason.
-You can force a queue run
-using the
-.b \-q
-flag (with no value).
-It is entertaining to use the
-.b \-v
-flag (verbose)
-when this is done to watch what happens:
-.(b
-/usr/\*(SD/sendmail \-q \-v
-.)b
-.pp
-You can also limit the jobs to those with a particular queue identifier,
-sender, or recipient
-using one of the queue modifiers.
-For example,
-.q \-qRberkeley
-restricts the queue run to jobs that have the string
-.q berkeley
-somewhere in one of the recipient addresses.
-Similarly,
-.q \-qSstring
-limits the run to particular senders and
-.q \-qIstring
-limits it to particular queue identifiers.
-.sh 2 "Debugging"
-.pp
-There are a fairly large number of debug flags
-built into
-.i sendmail .
-Each debug flag has a number and a level,
-where higher levels means to print out more information.
-The convention is that levels greater than nine are
-.q absurd,
-i.e.,
-they print out so much information that you wouldn't normally
-want to see them except for debugging that particular piece of code.
-Debug flags are set using the
-.b \-d
-option;
-the syntax is:
-.(b
-.ta \w'debug-option  'u
-debug-flag:	\fB\-d\fP debug-list
-debug-list:	debug-option [ , debug-option ]*
-debug-option:	debug-range [ . debug-level ]
-debug-range:	integer | integer \- integer
-debug-level:	integer
-.)b
-where spaces are for reading ease only.
-For example,
-.(b
-\-d12	Set flag 12 to level 1
-\-d12.3	Set flag 12 to level 3
-\-d3\-17	Set flags 3 through 17 to level 1
-\-d3\-17.4	Set flags 3 through 17 to level 4
-.)b
-For a complete list of the available debug flags
-you will have to look at the code
-(they are too dynamic to keep this documentation up to date).
-.sh 2 "Changing the Values of Options"
-.pp
-Options can be overridden using the
-.b \-o
-or
-.b \-O
-command line flags.
-For example,
-.(b
-/usr/\*(SD/sendmail \-oT2m
-.)b
-sets the
-.b T
-(timeout) option to two minutes
-for this run only;
-the equivalent line using the long option name is
-.(b
-/usr/\*(SD/sendmail -OTimeout.queuereturn=2m
-.)b
-.pp
-Some options have security implications.
-Sendmail allows you to set these,
-but relinquishes its setuid root permissions thereafter\**.
-.(f
-\**That is, it sets its effective uid to the real uid;
-thus, if you are executing as root,
-as from root's crontab file or during system startup
-the root permissions will still be honored.
-.)f
-.sh 2 "Trying a Different Configuration File"
-.pp
-An alternative configuration file
-can be specified using the
-.b \-C
-flag; for example,
-.(b
-/usr/\*(SD/sendmail \-Ctest.cf \-oQ/tmp/mqueue
-.)b
-uses the configuration file
-.i test.cf
-instead of the default
-.i /etc/sendmail.cf.
-If the
-.b \-C
-flag has no value
-it defaults to
-.i sendmail.cf
-in the current directory.
-.pp
-.i Sendmail
-gives up its setuid root permissions
-when you use this flag, so it is common to use a publicly writable directory
-(such as /tmp)
-as the spool directory (QueueDirectory or Q option) while testing.
-.sh 2 "Logging Traffic"
-.pp
-Many SMTP implementations do not fully implement the protocol.
-For example, some personal computer based SMTPs
-do not understand continuation lines in reply codes.
-These can be very hard to trace.
-If you suspect such a problem, you can set traffic logging using the
-.b \-X
-flag.
-For example,
-.(b
-/usr/\*(SD/sendmail \-X /tmp/traffic \-bd
-.)b
-will log all traffic in the file
-.i /tmp/traffic .
-.pp
-This logs a lot of data very quickly and should
-.b NEVER
-be used
-during normal operations.
-After starting up such a daemon,
-force the errant implementation to send a message to your host.
-All message traffic in and out of
-.i sendmail ,
-including the incoming SMTP traffic,
-will be logged in this file.
-.sh 2 "Testing Configuration Files"
-.pp
-When you build a configuration table,
-you can do a certain amount of testing
-using the
-.q "test mode"
-of
-.i sendmail .
-For example,
-you could invoke
-.i sendmail
-as:
-.(b
-sendmail \-bt \-Ctest.cf
-.)b
-which would read the configuration file
-.q test.cf
-and enter test mode.
-In this mode,
-you enter lines of the form:
-.(b
-rwset address
-.)b
-where
-.i rwset
-is the rewriting set you want to use
-and
-.i address
-is an address to apply the set to.
-Test mode shows you the steps it takes
-as it proceeds,
-finally showing you the address it ends up with.
-You may use a comma separated list of rwsets
-for sequential application of rules to an input.
-For example:
-.(b
-3,1,21,4 monet:bollard
-.)b
-first applies ruleset three to the input
-.q monet:bollard.
-Ruleset one is then applied to the output of ruleset three,
-followed similarly by rulesets twenty-one and four.
-.pp
-If you need more detail,
-you can also use the
-.q \-d21
-flag to turn on more debugging.
-For example,
-.(b
-sendmail \-bt \-d21.99
-.)b
-turns on an incredible amount of information;
-a single word address
-is probably going to print out several pages worth of information.
-.pp
-You should be warned that internally,
-.i sendmail
-applies ruleset 3 to all addresses.
-In test mode
-you will have to do that manually.
-For example, older versions allowed you to use
-.(b
-0 bruce@broadcast.sony.com
-.)b
-This version requires that you use:
-.(b
-3,0 bruce@broadcast.sony.com
-.)b
-.pp
-As of version 8.7,
-some other syntaxes are available in test mode:
-.bu
-\&.D\|x\|value
-defines macro
-.i x
-to have the indicated
-.i value .
-This is useful when debugging rules that use the
-.b $& \c
-.i x
-syntax.
-.bu
-\&.C\|c\|value
-adds the indicated
-.i value
-to class
-.i c .
-.bu
-\&.S\|ruleset
-dumps the contents of the indicated ruleset.
-.bu
-\-d\|debug-spec
-is equivalent to the command-line flag.
-.sh 2 "Persistent Host Status Information"
-.pp
-When
-.b HostStatusDirectory
-is enabled,
-information about the status of hosts is maintained on disk
-and can thus be shared between different instantiations of
-.i sendmail .
-The status of the last connection with each remote host
-may be viewed with the command:
-.(b
-sendmail \-bh
-.)b
-This information may be flushed with the command:
-.(b
-sendmail \-bH
-.)b
-Flushing the information prevents new
-.i sendmail 
-processes from loading it,
-but does not prevent existing processes from using the status information
-that they already have.
-.sh 1 "TUNING"
-.pp
-There are a number of configuration parameters
-you may want to change,
-depending on the requirements of your site.
-Most of these are set
-using an option in the configuration file.
-For example,
-the line
-.q "O Timeout.queuereturn=5d"
-sets option
-.q Timeout.queuereturn
-to the value
-.q 5d
-(five days).
-.pp
-Most of these options have appropriate defaults for most sites.
-However,
-sites having very high mail loads may find they need to tune them
-as appropriate for their mail load.
-In particular,
-sites experiencing a large number of small messages,
-many of which are delivered to many recipients,
-may find that they need to adjust the parameters
-dealing with queue priorities.
-.pp
-All versions of
-.i sendmail
-prior to 8.7
-had single character option names.
-As of 8.7,
-options have long (multi-character names).
-Although old short names are still accepted,
-most new options do not have short equivalents.
-.pp
-This section only describes the options you are most likely
-to want to tweak;
-read section
-.\"XREF
-5
-for more details.
-.sh 2 "Timeouts"
-.pp
-All time intervals are set
-using a scaled syntax.
-For example,
-.q 10m
-represents ten minutes, whereas
-.q 2h30m
-represents two and a half hours.
-The full set of scales is:
-.(b
-.ta 4n
-s	seconds
-m	minutes
-h	hours
-d	days
-w	weeks
-.)b
-.sh 3 "Queue interval"
-.pp
-The argument to the
-.b \-q
-flag
-specifies how often a sub-daemon will run the queue.
-This is typically set to between fifteen minutes
-and one hour.
-RFC 1123 section 5.3.1.1 recommends that this be at least 30 minutes.
-.sh 3 "Read timeouts"
-.pp
-Timeouts all have option names
-.q Timeout.\fIsuboption\fP .
-The recognized
-.i suboption s,
-their default values, and the minimum values
-allowed by RFC 1123 section 5.3.2 are:
-.nr ii 1i
-.ip connect
-The time to wait for an SMTP connection to open
-(the
-.i connect (2)
-system call)
-[0, unspecified].
-If zero, uses the kernel default.
-In no case can this option extend the timeout
-longer than the kernel provides, but it can shorten it.
-This is to get around kernels that provide an absurdly long connection timeout
-(90 minutes in one case).
-.ip iconnect
-The same as
-.i connect,
-except it applies only to the initial attempt to connect to a host
-for a given message
-[0, unspecified].
-The concept is that this should be very short (a few seconds);
-hosts that are well connected and responsive will thus be serviced immediately.
-Hosts that are slow will not hold up other deliveries in the initial
-delivery attempt.
-.ip initial
-The wait for the initial 220 greeting message
-[5m, 5m].
-.ip helo
-The wait for a reply from a HELO or EHLO command
-[5m, unspecified].
-This may require a host name lookup, so
-five minutes is probably a reasonable minimum.
-.ip mail\(dg
-The wait for a reply from a MAIL command
-[10m, 5m].
-.ip rcpt\(dg
-The wait for a reply from a RCPT command
-[1h, 5m].
-This should be long
-because it could be pointing at a list
-that takes a long time to expand
-(see below).
-.ip datainit\(dg
-The wait for a reply from a DATA command
-[5m, 2m].
-.ip datablock\(dg
-The wait for reading a data block
-(that is, the body of the message).
-[1h, 3m].
-This should be long because it also applies to programs
-piping input to
-.i sendmail
-which have no guarantee of promptness.
-.ip datafinal\(dg
-The wait for a reply from the dot terminating a message.
-[1h, 10m].
-If this is shorter than the time actually needed
-for the receiver to deliver the message,
-duplicates will be generated.
-This is discussed in RFC 1047.
-.ip rset
-The wait for a reply from a RSET command
-[5m, unspecified].
-.ip quit
-The wait for a reply from a QUIT command
-[2m, unspecified].
-.ip misc
-The wait for a reply from miscellaneous (but short) commands
-such as NOOP (no-operation) and VERB (go into verbose mode).
-[2m, unspecified].
-.ip command\(dg
-In server SMTP,
-the time to wait for another command.
-[1h, 5m].
-.ip ident
-The timeout waiting for a reply to an IDENT query
-[30s\**, unspecified].
-.(f
-\**On some systems the default is zero to turn the protocol off entirely.
-.)f
-.lp
-For compatibility with old configuration files,
-if no
-.i suboption
-is specified,
-all the timeouts marked with \(dg are set to the indicated value.
-.pp
-Many of the RFC 1123 minimum values
-may well be too short.
-.i Sendmail
-was designed to the RFC 822 protocols,
-which did not specify read timeouts;
-hence, versions of
-.i sendmail
-prior to version 8.1 did not guarantee to reply to messages promptly.
-In particular, a
-.q RCPT
-command specifying a mailing list
-will expand and verify the entire list;
-a large list on a slow system
-may easily take more than five minutes\**.
-.(f
-\**This verification includes looking up every address
-with the name server;
-this involves network delays,
-and can in some cases can be considerable.
-.)f
-I recommend a one hour timeout \*-
-since a communications failure during the RCPT phase is rare,
-a long timeout is not onerous
-and may ultimately help reduce network load
-and duplicated messages.
-.pp
-For example, the lines:
-.(b
-O Timeout.command=25m
-O Timeout.datablock=3h
-.)b
-sets the server SMTP command timeout to 25 minutes
-and the input data block timeout to three hours.
-.sh 3 "Message timeouts"
-.pp
-After sitting in the queue for a few days,
-a message will time out.
-This is to insure that at least the sender is aware
-of the inability to send a message.
-The timeout is typically set to five days.
-It is sometimes considered convenient to also send a warning message
-if the message is in the queue longer than a few hours
-(assuming you normally have good connectivity;
-if your messages normally took several hours to send
-you wouldn't want to do this because it wouldn't be an unusual event).
-These timeouts are set using the
-.b Timeout.queuereturn
-and
-.b Timeout.queuewarn
-options in the configuration file
-(previously both were set using the
-.b T
-option).
-.pp
-Since these options are global,
-and since you can not know
-.i "a priori"
-how long another host outside your domain will be down,
-a five day timeout is recommended.
-This allows a recipient to fix the problem even if it occurs
-at the beginning of a long weekend.
-RFC 1123 section 5.3.1.1 says that this parameter
-should be ``at least 4\-5 days''.
-.pp
-The
-.b Timeout.queuewarn
-value can be piggybacked on the
-.b T
-option by indicating a time after which
-a warning message should be sent;
-the two timeouts are separated by a slash.
-For example, the line
-.(b
-OT5d/4h
-.)b
-causes email to fail after five days,
-but a warning message will be sent after four hours.
-This should be large enough that the message will have been tried
-several times.
-.sh 2 "Forking During Queue Runs"
-.pp
-By setting the
-.b ForkEachJob
-(\c
-.b Y )
-option,
-.i sendmail
-will fork before each individual message
-while running the queue.
-This will prevent
-.i sendmail
-from consuming large amounts of memory,
-so it may be useful in memory-poor environments.
-However, if the
-.b ForkEachJob
-option is not set,
-.i sendmail
-will keep track of hosts that are down during a queue run,
-which can improve performance dramatically.
-.pp
-If the
-.b ForkEachJob
-option is set,
-.i sendmail
-can not use connection caching.
-.sh 2 "Queue Priorities"
-.pp
-Every message is assigned a priority when it is first instantiated,
-consisting of the message size (in bytes)
-offset by the message class
-(which is determined from the Precedence: header)
-times the
-.q "work class factor"
-and the number of recipients times the
-.q "work recipient factor."
-The priority is used to order the queue.
-Higher numbers for the priority mean that the message will be processed later
-when running the queue.
-.pp
-The message size is included so that large messages are penalized
-relative to small messages.
-The message class allows users to send
-.q "high priority"
-messages by including a
-.q Precedence:
-field in their message;
-the value of this field is looked up in the
-.b P
-lines of the configuration file.
-Since the number of recipients affects the amount of load a message presents
-to the system,
-this is also included into the priority.
-.pp
-The recipient and class factors
-can be set in the configuration file using the
-.b RecipientFactor
-(\c
-.b y )
-and
-.b ClassFactor
-(\c
-.b z )
-options respectively.
-They default to 30000 (for the recipient factor)
-and 1800
-(for the class factor).
-The initial priority is:
-.EQ
-pri = msgsize - (class times bold ClassFactor) + (nrcpt times bold RecipientFactor)
-.EN
-(Remember, higher values for this parameter actually mean
-that the job will be treated with lower priority.)
-.pp
-The priority of a job can also be adjusted each time it is processed
-(that is, each time an attempt is made to deliver it)
-using the
-.q "work time factor,"
-set by the
-.b RetryFactor
-(\c
-.b Z )
-option.
-This is added to the priority,
-so it normally decreases the precedence of the job,
-on the grounds that jobs that have failed many times
-will tend to fail again in the future.
-The
-.b RetryFactor
-option defaults to 90000.
-.sh 2 "Load Limiting"
-.pp
-.i Sendmail
-can be asked to queue (but not deliver)
-mail if the system load average gets too high
-using the
-.b QueueLA
-(\c
-.b x )
-option.
-When the load average exceeds the value of the
-.b QueueLA
-option,
-the delivery mode is set to
-.b q
-(queue only)
-if the
-.b QueueFactor
-(\c
-.b q )
-option divided by the difference in the current load average and the
-.b QueueLA
-option
-plus one
-exceeds the priority of the message \(em
-that is, the message is queued iff:
-.EQ
-pri > { bold QueueFactor } over { LA - { bold QueueLA } + 1 }
-.EN
-The
-.b QueueFactor
-option defaults to 600000,
-so each point of load average is worth 600000
-priority points
-(as described above).
-.pp
-For drastic cases,
-the
-.b RefuseLA
-(\c
-.b X )
-option defines a load average at which
-.i sendmail
-will refuse
-to accept network connections.
-Locally generated mail
-(including incoming UUCP mail)
-is still accepted.
-.sh 2 "Delivery Mode"
-.pp
-There are a number of delivery modes that
-.i sendmail
-can operate in,
-set by the
-.b DeliveryMode
-(\c
-.b d )
-configuration option.
-These modes
-specify how quickly mail will be delivered.
-Legal modes are:
-.(b
-.ta 4n
-i	deliver interactively (synchronously)
-b	deliver in background (asynchronously)
-q	queue only (don't deliver)
-d	defer delvery attempts (don't deliver)
-.)b
-There are tradeoffs.
-Mode
-.q i
-gives the sender the quickest feedback,
-but may slow down some mailers and
-is hardly ever necessary.
-Mode
-.q b
-delivers promptly but
-can cause large numbers of processes
-if you have a mailer that takes a long time to deliver a message.
-Mode
-.q q
-minimizes the load on your machine,
-but means that delivery may be delayed for up to the queue interval.
-Mode
-.q d
-is identical to mode
-.q q
-except that it also prevents all the early map lookups from working;
-it is intended for ``dial on demand'' sites where DNS lookups
-might cost real money.
-Some simple error messages
-(e.g., host unknown during the SMTP protocol)
-will be delayed using this mode.
-Mode
-.q b
-is the usual default.
-.pp
-If you run in mode
-.q q
-(queue only),
-.q d
-(defer),
-or
-.q b
-(deliver in background)
-.i sendmail
-will not expand aliases and follow .forward files
-upon initial receipt of the mail.
-This speeds up the response to RCPT commands.
-Mode
-.q i
-cannot be used by the SMTP server.
-.sh 2 "Log Level"
-.pp
-The level of logging can be set for
-.i sendmail .
-The default using a standard configuration table is level 9.
-The levels are as follows:
-.nr ii 0.5i
-.ip 0
-No logging.
-.ip 1
-Serious system failures and potential security problems.
-.ip 2
-Lost communications (network problems) and protocol failures.
-.ip 3
-Other serious failures.
-.ip 4
-Minor failures.
-.ip 5
-Message collection statistics.
-.ip 6
-Creation of error messages,
-VRFY and EXPN commands.
-.ip 7
-Delivery failures (host or user unknown, etc.).
-.ip 8
-Successful deliveries and alias database rebuilds.
-.ip 9
-Messages being deferred
-(due to a host being down, etc.).
-.ip 10
-Database expansion (alias, forward, and userdb lookups).
-.ip 12
-Log all incoming and outgoing SMTP commands.
-.ip 20
-Logs attempts to run locked queue files.
-These are not errors,
-but can be useful to note if your queue appears to be clogged.
-.ip 30
-Lost locks (only if using lockf instead of flock).
-.lp
-Additionally,
-values above 64 are reserved for extremely verbose debugging output.
-No normal site would ever set these.
-.sh 2 "File Modes"
-.pp
-The modes used for files depend on what functionality you want
-and the level of security you require.
-.sh 3 "To suid or not to suid?"
-.pp
-.i Sendmail
-can safely be made
-setuid to root.
-At the point where it is about to
-.i exec \|(2)
-a mailer,
-it checks to see if the userid is zero;
-if so,
-it resets the userid and groupid to a default
-(set by the
-.b u
-and
-.b g
-options).
-(This can be overridden
-by setting the
-.b S
-flag to the mailer
-for mailers that are trusted
-and must be called as root.)
-However,
-this will cause mail processing
-to be accounted
-(using
-.i sa \|(8))
-to root
-rather than to the user sending the mail.
-.pp
-If you don't make
-.i sendmail
-setuid to root, it will still run but you lose a lot of functionality
-and a lot of privacy, since you'll have to make the queue directory
-world readable.
-You could also make
-.i sendmail
-setuid to some pseudo-user
-(e.g., create a user called
-.q sendmail
-and make
-.i sendmail
-setuid to that)
-which will fix the privacy problems
-but not the functionality issues.
-Also, this isn't a guarantee of security:
-for example,
-root occasionally sends mail,
-and the daemon often runs as root.
-.sh 3 "Should my alias database be writable?"
-.pp
-At Berkeley
-we have the alias database
-(/etc/aliases*)
-mode 644.
-While this is not as flexible as if the database
-were more 666, it avoids potential security problems
-with a globally writable database.
-.pp
-The database that
-.i sendmail
-actually used
-is represented by the two files
-.i aliases.dir
-and
-.i aliases.pag
-(both in /etc)
-(or
-.i aliases.db
-if you are running with the new Berkeley database primitives).
-The mode on these files should match the mode
-on /etc/aliases.
-If
-.i aliases
-is writable
-and the
-DBM
-files
-(\c
-.i aliases.dir
-and
-.i aliases.pag )
-are not,
-users will be unable to reflect their desired changes
-through to the actual database.
-However,
-if
-.i aliases
-is read-only
-and the DBM files are writable,
-a slightly sophisticated user
-can arrange to steal mail anyway.
-.pp
-If your DBM files are not writable by the world
-or you do not have auto-rebuild enabled
-(with the
-.b AutoRebuildAliases
-option),
-then you must be careful to reconstruct the alias database
-each time you change the text version:
-.(b
-newaliases
-.)b
-If this step is ignored or forgotten
-any intended changes will also be ignored or forgotten.
-.sh 2 "Connection Caching"
-.pp
-When processing the queue,
-.i sendmail
-will try to keep the last few open connections open
-to avoid startup and shutdown costs.
-This only applies to IPC connections.
-.pp
-When trying to open a connection
-the cache is first searched.
-If an open connection is found, it is probed to see if it is still active
-by sending a
-.sm RSET
-command.
-It is not an error if this fails;
-instead, the connection is closed and reopened.
-.pp
-Two parameters control the connection cache.
-The
-.b ConnectionCacheSize
-(\c
-.b k )
-option defines the number of simultaneous open connections
-that will be permitted.
-If it is set to zero,
-connections will be closed as quickly as possible.
-The default is one.
-This should be set as appropriate for your system size;
-it will limit the amount of system resources that
-.i sendmail
-will use during queue runs.
-Never set this higher than 4.
-.pp
-The
-.b ConnectionCacheTimeout
-(\c
-.b K )
-option specifies the maximum time that any cached connection
-will be permitted to idle.
-When the idle time exceeds this value
-the connection is closed.
-This number should be small
-(under ten minutes)
-to prevent you from grabbing too many resources
-from other hosts.
-The default is five minutes.
-.sh 2 "Name Server Access"
-.pp
-Control of host address lookups is set by the
-.b hosts
-service entry in your service switch file.
-If you are on a system that has built-in service switch support
-(e.g., Ultrix, Solaris, or DEC OSF/1)
-then your system is probably configured properly already.
-Otherwise,
-.i sendmail
-will consult the file
-.b /etc/service.switch ,
-which should be created.
-.i Sendmail
-only uses two entries:
-.b hosts
-and
-.b aliases .
-.pp
-However, some systems (such as SunOS)
-will do DNS lookups
-regardless of the setting of the service switch entry.
-In particular, the system routine
-.i gethostbyname (3)
-is used to look up host names,
-and many vendor versions try some combination of DNS, NIS,
-and file lookup in /etc/hosts
-without consulting a service switch.
-.i Sendmail
-makes no attempt to work around this problem,
-and the DNS lookup will be done anyway.
-If you do not have a nameserver configured at all,
-such as at a UUCP-only site,
-.i sendmail
-will get a
-.q "connection refused"
-message when it tries to connect to the name server.
-If the
-.b hosts
-switch entry has the service
-.q dns
-listed somewhere in the list,
-.i sendmail
-will interpret this to mean a temporary failure
-and will queue the mail for later processing;
-otherwise, it ignores the name server data.
-.pp
-The same technique is used to decide whether to do MX lookups.
-If you want MX support, you
-.i must
-have
-.q dns
-listed as a service in the
-.b hosts
-switch entry.
-.pp
-The
-.b ResolverOptions
-(\c
-.b I )
-option allows you to tweak name server options.
-The command line takes a series of flags as documented in
-.i resolver (3)
-(with the leading
-.q RES_
-deleted).
-Each can be preceded by an optional `+' or `\(mi'.
-For example, the line
-.(b
-O ResolverOptions=+AAONLY \(miDNSRCH
-.)b
-turns on the AAONLY (accept authoritative answers only)
-and turns off the DNSRCH (search the domain path) options.
-Most resolver libraries default DNSRCH, DEFNAMES, and RECURSE
-flags on and all others off.
-You can also include
-.q HasWildcardMX
-to specify that there is a wildcard MX record matching your domain;
-this turns off MX matching when canonifying names,
-which can lead to inappropriate canonifications.
-.pp
-Version level 1 configurations
-turn DNSRCH and DEFNAMES off when doing delivery lookups,
-but leave them on everywhere else.
-Version 8 of
-.i sendmail
-ignores them when doing canonification lookups
-(that is, when using $[ ... $]),
-and always does the search.
-If you don't want to do automatic name extension,
-don't call $[ ... $].
-.pp
-The search rules for $[ ... $] are somewhat different than usual.
-If the name being looked up
-has at least one dot, it always tries the unmodified name first.
-If that fails, it tries the reduced search path,
-and lastly tries the unmodified name
-(but only for names without a dot,
-since names with a dot have already been tried).
-This allows names such as
-``utc.CS''
-to match the site in Czechoslovakia
-rather than the site in your local Computer Science department.
-It also prefers A and CNAME records over MX records \*-
-that is, if it finds an MX record it makes note of it,
-but keeps looking.
-This way, if you have a wildcard MX record matching your domain,
-it will not assume that all names match.
-.pp
-To completely turn off all name server access
-on systems without service switch support
-(such as SunOS)
-you will have to recompile with
-\-DNAMED_BIND=0
-and remove \-lresolv from the list of libraries to be searched
-when linking.
-.sh 2 "Moving the Per-User Forward Files"
-.pp
-Some sites mount each user's home directory
-from a local disk on their workstation,
-so that local access is fast.
-However, the result is that .forward file lookups are slow.
-In some cases,
-mail can even be delivered on machines inappropriately
-because of a file server being down.
-The performance can be especially bad if you run the automounter.
-.pp
-The
-.b ForwardPath
-(\c
-.b J )
-option allows you to set a path of forward files.
-For example, the config file line
-.(b
-O ForwardPath=/var/forward/$u:$z/.forward.$w
-.)b
-would first look for a file with the same name as the user's login
-in /var/forward;
-if that is not found (or is inaccessible)
-the file
-``.forward.\c
-.i machinename ''
-in the user's home directory is searched.
-A truly perverse site could also search by sender
-by using $r, $s, or $f.
-.pp
-If you create a directory such as /var/forward,
-it should be mode 1777
-(that is, the sticky bit should be set).
-Users should create the files mode 644.
-.sh 2 "Free Space"
-.pp
-On systems that have one of the system calls in the
-.i statfs (2)
-family
-(including
-.i statvfs
-and
-.i ustat ),
-you can specify a minimum number of free blocks on the queue filesystem
-using the
-.b MinFreeBlocks
-(\c
-.b b )
-option.
-If there are fewer than the indicated number of blocks free
-on the filesystem on which the queue is mounted
-the SMTP server will reject mail
-with the
-452 error code.
-This invites the SMTP client to try again later.
-.pp
-Beware of setting this option too high;
-it can cause rejection of email
-when that mail would be processed without difficulty.
-.sh 2 "Maximum Message Size"
-.pp
-To avoid overflowing your system with a large message,
-the
-.b MaxMessageSize
-option can be set to set an absolute limit
-on the size of any one message.
-This will be advertised in the ESMTP dialogue
-and checked during message collection.
-.sh 2 "Privacy Flags"
-.pp
-The
-.b PrivacyOptions
-(\c
-.b p )
-option allows you to set certain
-``privacy''
-flags.
-Actually, many of them don't give you any extra privacy,
-rather just insisting that client SMTP servers
-use the HELO command
-before using certain commands
-or adding extra headers to indicate possible spoof attempts.
-.pp
-The option takes a series of flag names;
-the final privacy is the inclusive or of those flags.
-For example:
-.(b
-O PrivacyOptions=needmailhelo, noexpn
-.)b
-insists that the HELO or EHLO command be used before a MAIL command is accepted
-and disables the EXPN command.
-.pp
-The flags are detailed in section
-.\"XREF
-5.6.
-.sh 2 "Send to Me Too"
-.pp
-Normally,
-.i sendmail
-deletes the (envelope) sender from any list expansions.
-For example, if
-.q matt
-sends to a list that contains
-.q matt
-as one of the members he won't get a copy of the message.
-If the
-.b \-m
-(me too)
-command line flag, or if the
-.b MeToo
-(\c
-.b m )
-option is set in the configuration file,
-this behaviour is suppressed.
-Some sites like to run the
-.sm SMTP
-daemon with
-.b \-m .
-.sh 1 "THE WHOLE SCOOP ON THE CONFIGURATION FILE"
-.pp
-This section describes the configuration file
-in detail.
-.pp
-There is one point that should be made clear immediately:
-the syntax of the configuration file
-is designed to be reasonably easy to parse,
-since this is done every time
-.i sendmail
-starts up,
-rather than easy for a human to read or write.
-On the
-.q "future project"
-list is a
-configuration-file compiler.
-.pp
-The configuration file is organized as a series of lines,
-each of which begins with a single character
-defining the semantics for the rest of the line.
-Lines beginning with a space or a tab
-are continuation lines
-(although the semantics are not well defined in many places).
-Blank lines and lines beginning with a sharp symbol
-(`#')
-are comments.
-.sh 2 "R and S \*- Rewriting Rules"
-.pp
-The core of address parsing
-are the rewriting rules.
-These are an ordered production system.
-.i Sendmail
-scans through the set of rewriting rules
-looking for a match on the left hand side
-(LHS)
-of the rule.
-When a rule matches,
-the address is replaced by the right hand side
-(RHS)
-of the rule.
-.pp
-There are several sets of rewriting rules.
-Some of the rewriting sets are used internally
-and must have specific semantics.
-Other rewriting sets
-do not have specifically assigned semantics,
-and may be referenced by the mailer definitions
-or by other rewriting sets.
-.pp
-The syntax of these two commands are:
-.(b F
-.b S \c
-.i n
-.)b
-Sets the current ruleset being collected to
-.i n .
-If you begin a ruleset more than once
-it appends to the old definition.
-.(b F
-.b R \c
-.i lhs
-.i rhs
-.i comments
-.)b
-The
-fields must be separated
-by at least one tab character;
-there may be embedded spaces
-in the fields.
-The
-.i lhs
-is a pattern that is applied to the input.
-If it matches,
-the input is rewritten to the
-.i rhs .
-The
-.i comments
-are ignored.
-.pp
-Macro expansions of the form
-.b $ \c
-.i x
-are performed when the configuration file is read.
-Expansions of the form
-.b $& \c
-.i x
-are performed at run time using a somewhat less general algorithm.
-This for is intended only for referencing internally defined macros
-such as
-.b $h
-that are changed at runtime.
-.sh 3 "The left hand side"
-.pp
-The left hand side of rewriting rules contains a pattern.
-Normal words are simply matched directly.
-Metasyntax is introduced using a dollar sign.
-The metasymbols are:
-.(b
-.ta \w'\fB$=\fP\fIx\fP  'u
-\fB$*\fP	Match zero or more tokens
-\fB$+\fP	Match one or more tokens
-\fB$\-\fP	Match exactly one token
-\fB$=\fP\fIx\fP	Match any phrase in class \fIx\fP
-\fB$~\fP\fIx\fP	Match any word not in class \fIx\fP
-.)b
-If any of these match,
-they are assigned to the symbol
-.b $ \c
-.i n
-for replacement on the right hand side,
-where
-.i n
-is the index in the LHS.
-For example,
-if the LHS:
-.(b
-$\-:$+
-.)b
-is applied to the input:
-.(b
-UCBARPA:eric
-.)b
-the rule will match, and the values passed to the RHS will be:
-.(b
-.ta 4n
-$1	UCBARPA
-$2	eric
-.)b
-.pp
-Additionally, the LHS can include
-.b $@
-to match zero tokens.
-This is
-.i not
-bound to a
-.b $ \c
-.i n
-on the RHS, and is normally only used when it stands alone
-in order to match the null input.
-.sh 3 "The right hand side"
-.pp
-When the left hand side of a rewriting rule matches,
-the input is deleted and replaced by the right hand side.
-Tokens are copied directly from the RHS
-unless they begin with a dollar sign.
-Metasymbols are:
-.(b
-.ta \w'$#mailer\0\0\0'u
-\fB$\fP\fIn\fP	Substitute indefinite token \fIn\fP from LHS
-\fB$[\fP\fIname\fP\fB$]\fP	Canonicalize \fIname\fP
-\fB$(\fP\fImap key\fP \fB$@\fP\fIarguments\fP \fB$:\fP\fIdefault\fP \fB$)\fP
-	Generalized keyed mapping function
-\fB$>\fP\fIn\fP	\*(lqCall\*(rq ruleset \fIn\fP
-\fB$#\fP\fImailer\fP	Resolve to \fImailer\fP
-\fB$@\fP\fIhost\fP	Specify \fIhost\fP
-\fB$:\fP\fIuser\fP	Specify \fIuser\fP
-.)b
-.pp
-The
-.b $ \c
-.i n
-syntax substitutes the corresponding value from a
-.b $+ ,
-.b $\- ,
-.b $* ,
-.b $= ,
-or
-.b $~
-match on the LHS.
-It may be used anywhere.
-.pp
-A host name enclosed between
-.b $[
-and
-.b $]
-is looked up in the host database(s)
-and replaced by the canonical name\**.
-.(f
-\**This is actually
-completely equivalent
-to $(host \fIhostname\fP$).
-In particular, a
-.b $:
-default can be used.
-.)f
-For example,
-.q $[ftp$]
-might become
-.q ftp.CS.Berkeley.EDU
-and
-.q $[[128.32.130.2]$]
-would become
-.q vangogh.CS.Berkeley.EDU.
-.i Sendmail
-recognizes it's numeric IP address
-without calling the name server
-and replaces it with it's canonical name.
-.pp
-The
-.b $(
-\&...
-.b $)
-syntax is a more general form of lookup;
-it uses a named map instead of an implicit map.
-If no lookup is found, the indicated
-.i default
-is inserted;
-if no default is specified and no lookup matches,
-the value is left unchanged.
-The
-.i arguments
-are passed to the map for possible use.
-.pp
-The
-.b $> \c
-.i n
-syntax
-causes the remainder of the line to be substituted as usual
-and then passed as the argument to ruleset
-.i n .
-The final value of ruleset
-.i n
-then becomes
-the substitution for this rule.
-The
-.b $>
-syntax can only be used at the beginning of the right hand side;
-it can be only be preceded by
-.b $@
-or
-.b $: .
-.pp
-The
-.b $#
-syntax should
-.i only
-be used in ruleset zero
-or a subroutine of ruleset zero.
-It causes evaluation of the ruleset to terminate immediately,
-and signals to
-.i sendmail
-that the address has completely resolved.
-The complete syntax is:
-.(b
-\fB$#\fP\fImailer\fP \fB$@\fP\fIhost\fP \fB$:\fP\fIuser\fP
-.)b
-This specifies the
-{mailer, host, user}
-3-tuple necessary to direct the mailer.
-If the mailer is local
-the host part may be omitted\**.
-.(f
-\**You may want to use it for special
-.q "per user"
-extensions.
-For example, in the address
-.q jgm+foo@CMU.EDU ;
-the
-.q +foo
-part is not part of the user name,
-and is passed to the local mailer for local use.
-.)f
-The
-.i mailer
-must be a single word,
-but the
-.i host
-and
-.i user
-may be multi-part.
-If the
-.i mailer
-is the builtin IPC mailer,
-the
-.i host
-may be a colon-separated list of hosts
-that are searched in order for the first working address
-(exactly like MX records).
-The
-.i user
-is later rewritten by the mailer-specific envelope rewriting set
-and assigned to the
-.b $u
-macro.
-As a special case, if the mailer specified has the
-.b F=@
-flag specified
-and the first character of the
-.b $:
-value is
-.q @ ,
-the
-.q @
-is stripped off, and a flag is set in the address descriptor
-that causes sendmail to not do ruleset 5 processing.
-.pp
-Normally, a rule that matches is retried,
-that is,
-the rule loops until it fails.
-A RHS may also be preceded by a
-.b $@
-or a
-.b $:
-to change this behavior.
-A
-.b $@
-prefix causes the ruleset to return with the remainder of the RHS
-as the value.
-A
-.b $:
-prefix causes the rule to terminate immediately,
-but the ruleset to continue;
-this can be used to avoid continued application of a rule.
-The prefix is stripped before continuing.
-.pp
-The
-.b $@
-and
-.b $:
-prefixes may precede a
-.b $>
-spec;
-for example:
-.(b
-.ta 8n
-R$+	$: $>7 $1
-.)b
-matches anything,
-passes that to ruleset seven,
-and continues;
-the
-.b $:
-is necessary to avoid an infinite loop.
-.pp
-Substitution occurs in the order described,
-that is,
-parameters from the LHS are substituted,
-hostnames are canonicalized,
-.q subroutines
-are called,
-and finally
-.b $# ,
-.b $@ ,
-and
-.b $:
-are processed.
-.sh 3 "Semantics of rewriting rule sets"
-.pp
-There are five rewriting sets
-that have specific semantics.
-Four of these are related as depicted by figure 1.
-.(z
-.hl
-.ie n \{\
-.(c
-                    +---+
-                 -->| 0 |-->resolved address
-                /   +---+
-               /            +---+   +---+
-              /        ---->| 1 |-->| S |--
-       +---+ / +---+  /     +---+   +---+  \e    +---+
-addr-->| 3 |-->| D |--                      --->| 4 |-->msg
-       +---+   +---+  \e     +---+   +---+  /    +---+
-                        --->| 2 |-->| R |--
-                            +---+   +---+
-.)c
-
-.\}
-.el .ie !"\*(.T"" \
-\{\
-.PS
-boxwid = 0.3i
-boxht = 0.3i
-movewid = 0.3i
-moveht = 0.3i
-linewid = 0.3i
-lineht = 0.3i
-
-	box invis "addr"; arrow
-Box3:	box "3"
-A1:	arrow
-BoxD:	box "D"; line; L1: Here
-C:	[
-	C1:	arrow; box "1"; arrow; box "S"; line; E1: Here
-		move to C1 down 0.5; right
-	C2:	arrow; box "2"; arrow; box "R"; line; E2: Here
-	] with .w at L1 + (0.5, 0)
-	move to C.e right 0.5
-L4:	arrow; box "4"; arrow; box invis "msg"
-	line from L1 to C.C1
-	line from L1 to C.C2
-	line from C.E1 to L4
-	line from C.E2 to L4
-	move to BoxD.n up 0.6; right
-Box0:	arrow; box "0"
-	arrow; box invis "resolved address" width 1.3
-	line from 1/3 of the way between A1 and BoxD.w to Box0
-.PE
-.\}
-.el .sp 2i
-.ce
-Figure 1 \*- Rewriting set semantics
-.(c
-D \*- sender domain addition
-S \*- mailer-specific sender rewriting
-R \*- mailer-specific recipient rewriting
-.)c
-.hl
-.)z
-.pp
-Ruleset three
-should turn the address into
-.q "canonical form."
-This form should have the basic syntax:
-.(b
-local-part@host-domain-spec
-.)b
-Ruleset three
-is applied by
-.i sendmail
-before doing anything with any address.
-.pp
-If no
-.q @
-sign is specified,
-then the
-host-domain-spec
-.i may
-be appended (box
-.q D
-in Figure 1)
-from the
-sender address
-(if the
-.b C
-flag is set in the mailer definition
-corresponding to the
-.i sending
-mailer).
-.pp
-Ruleset zero
-is applied after ruleset three
-to addresses that are going to actually specify recipients.
-It must resolve to a
-.i "{mailer, host, user}"
-triple.
-The
-.i mailer
-must be defined in the mailer definitions
-from the configuration file.
-The
-.i host
-is defined into the
-.b $h
-macro
-for use in the argv expansion of the specified mailer.
-.pp
-Rulesets one and two
-are applied to all sender and recipient addresses respectively.
-They are applied before any specification
-in the mailer definition.
-They must never resolve.
-.pp
-Ruleset four is applied to all addresses
-in the message.
-It is typically used
-to translate internal to external form.
-.pp
-In addition,
-ruleset 5 is applied to all local addresses
-(specifically, those that resolve to a mailer with the `F=5'
-flag set)
-that do not have aliases.
-This allows a last minute hook for local names.
-.sh 3 "Ruleset hooks"
-.pp
-A few extra rulesets are defined as
-.q hooks
-that can be defined to get special features.
-They are all named rulesets.
-The
-.q check_*
-forms all give accept/reject status;
-falling off the end or returning normally is an accept,
-and resolving to $#error
-is a reject.
-.sh 4 "check_relay"
-.pp
-The
-.i check_relay
-ruleset is called after a connection is accepted.
-It is passed
-.(b
-client.host.name $| client.host.address
-.)b
-where
-.b $|
-is a metacharacter separating the two parts.
-This ruleset can reject connections from various locations.
-.sh 4 "check_mail"
-.pp
-The
-.i check_mail
-ruleset is passed the user name parameter of the
-.sm "SMTP MAIL"
-command.
-It can accept or reject the address.
-.sh 4 "check_rcpt"
-.pp
-The
-.i check_rcpt
-ruleset is passed the user name parameter of the
-.sm "SMTP RCPT"
-command.
-It can accept or reject the address.
-.sh 4 "check_compat"
-.pp
-The
-.i check_compat
-ruleset is passed
-.(b
-sender-address $| recipient-address
-.)b
-where
-.b $|
-is a metacharacter separating the addresses.
-It can accept or reject mail transfer between these two addresses
-much like the
-.i checkcompat()
-function.
-.sh 3 "IPC mailers"
-.pp
-Some special processing occurs
-if the ruleset zero resolves to an IPC mailer
-(that is, a mailer that has
-.q [IPC]
-listed as the Path in the
-.b M
-configuration line.
-The host name passed after
-.q $@
-has MX expansion performed;
-this looks the name up in DNS to find alternate delivery sites.
-.pp
-The host name can also be provided as a dotted quad in square brackets;
-for example:
-.(b
-[128.32.149.78]
-.)b
-This causes direct conversion of the numeric value
-to a TCP/IP host address.
-.pp
-The host name passed in after the
-.q $@
-may also be a colon-separated list of hosts.
-Each is separately MX expanded and the results are concatenated
-to make (essentially) one long MX list.
-The intent here is to create
-.q fake
-MX records that are not published in DNS
-for private internal networks.
-.pp
-As a final special case, the host name can be passed in
-as a text string
-in square brackets:
-.(b
-[ucbvax.berkeley.edu]
-.)b
-This form avoids the MX mapping.
-.b N.B.:
-.i
-This is intended only for situations where you have a network firewall
-or other host that will do special processing for all your mail,
-so that your MX record points to a gateway machine;
-this machine could then do direct delivery to machines
-within your local domain.
-Use of this feature directly violates RFC 1123 section 5.3.5:
-it should not be used lightly.
-.r
-.sh 2 "D \*- Define Macro"
-.pp
-Macros are named with a single character
-or with a word in {braces}.
-Single character names may be selected from the entire ASCII set,
-but user-defined macros
-should be selected from the set of upper case letters only.
-Lower case letters
-and special symbols
-are used internally.
-Long names beginning with a lower case letter or a punctuation character
-are reserved for use by sendmail,
-so user-defined long macro names should begin with an upper case letter.
-.pp
-The syntax for macro definitions is:
-.(b F
-.b D \c
-.i x\|val
-.)b
-where
-.i x
-is the name of the macro
-(which may be a single character
-or a word in braces)
-and
-.i val
-is the value it should have.
-There should be no spaces given
-that do not actually belong in the macro value.
-.pp
-Macros are interpolated
-using the construct
-.b $ \c
-.i x ,
-where
-.i x
-is the name of the macro to be interpolated.
-This interpolation is done when the configuration file is read,
-except in
-.b M
-lines.
-The special construct
-.b $& \c
-.i x
-can be used in
-.b R
-lines to get deferred interpolation.
-.pp
-Conditionals can be specified using the syntax:
-.(b
-$?x text1 $| text2 $.
-.)b
-This interpolates
-.i text1
-if the macro
-.b $x
-is set,
-and
-.i text2
-otherwise.
-The
-.q else
-(\c
-.b $| )
-clause may be omitted.
-.pp
-Lower case macro names are reserved to have
-special semantics,
-used to pass information in or out of
-.i sendmail ,
-and special characters are reserved to
-provide conditionals, etc.
-Upper case names
-(that is,
-.b $A
-through
-.b $Z )
-are specifically reserved for configuration file authors.
-.pp
-The following macros are defined and/or used internally by
-.i sendmail
-for interpolation into argv's for mailers
-or for other contexts.
-The ones marked \(dg are information passed into sendmail\**,
-.(f
-\**As of version 8.6,
-all of these macros have reasonable defaults.
-Previous versions required that they be defined.
-.)f
-the ones marked \(dd are information passed both in and out of sendmail,
-and the unmarked macros are passed out of sendmail
-but are not otherwise used internally.
-These macros are:
-.nr ii 5n
-.ip $a
-The origination date in RFC 822 format.
-This is extracted from the Date: line.
-.ip $b
-The current date in RFC 822 format.
-.ip $c
-The hop count.
-This is a count of the number of Received: lines
-plus the value of the
-.b \-h
-command line flag.
-.ip $d
-The current date in UNIX (ctime) format.
-.ip $e\(dg
-(Obsolete; use SmtpGreetingMessage option instead.)
-The SMTP entry message.
-This is printed out when SMTP starts up.
-The first word must be the
-.b $j
-macro as specified by RFC821.
-Defaults to
-.q "$j Sendmail $v ready at $b" .
-Commonly redefined to include the configuration version number, e.g.,
-.q "$j Sendmail $v/$Z ready at $b"
-.ip $f
-The envelope sender (from) address.
-.ip $g
-The sender address relative to the recipient.
-For example, if
-.b $f
-is
-.q foo ,
-.b $g
-will be
-.q host!foo ,
-.q foo@host.domain ,
-or whatever is appropriate for the receiving mailer.
-.ip $h
-The recipient host.
-This is set in ruleset 0 from the $# field of a parsed address.
-.ip $i
-The queue id,
-e.g.,
-.q HAA12345 .
-.ip $j\(dd
-The \*(lqofficial\*(rq domain name for this site.
-This is fully qualified if the full qualification can be found.
-It
-.i must
-be redefined to be the fully qualified domain name
-if your system is not configured so that information can find
-it automatically.
-.ip $k
-The UUCP node name (from the uname system call).
-.ip $l\(dg
-(Obsolete; use UnixFromLine option instead.)
-The format of the UNIX from line.
-Unless you have changed the UNIX mailbox format,
-you should not change the default,
-which is
-.q "From $g  $d" .
-.ip $m
-The domain part of the \fIgethostname\fP return value.
-Under normal circumstances,
-.b $j
-is equivalent to
-.b $w.$m .
-.ip $n\(dg
-The name of the daemon (for error messages).
-Defaults to
-.q MAILER-DAEMON .
-.ip $o\(dg
-(Obsolete: use OperatorChars option instead.)
-The set of \*(lqoperators\*(rq in addresses.
-A list of characters
-which will be considered tokens
-and which will separate tokens
-when doing parsing.
-For example, if
-.q @
-were in the
-.b $o
-macro, then the input
-.q a@b
-would be scanned as three tokens:
-.q a,
-.q @,
-and
-.q b.
-Defaults to
-.q ".:@[]" ,
-which is the minimum set necessary to do RFC 822 parsing;
-a richer set of operators is
-.q ".:%@!/[]" ,
-which adds support for UUCP, the %-hack, and X.400 addresses.
-.ip $p
-Sendmail's process id.
-.ip $q\(dg
-Default format of sender address.
-The
-.b $q
-macro specifies how an address should appear in a message
-when it is defaulted.
-Defaults to
-.q "<$g>" .
-It is commonly redefined to be
-.q "$?x$x <$g>$|$g$."
-or
-.q "$g$?x ($x)$." ,
-corresponding to the following two formats:
-.(b
-Eric Allman <eric@CS.Berkeley.EDU>
-eric@CS.Berkeley.EDU (Eric Allman)
-.)b
-.i Sendmail
-properly quotes names that have special characters
-if the first form is used.
-.ip $r
-Protocol used to receive the message.
-Set from the
-.b \-p
-command line flag or by the SMTP server code.
-.ip $s
-Sender's host name.
-Set from the
-.b \-p
-command line flag or by the SMTP server code.
-.ip $t
-A numeric representation of the current time.
-.ip $u
-The recipient user.
-.ip $v
-The version number of the
-.i sendmail
-binary.
-.ip $w\(dd
-The hostname of this site.
-This is the root name of this host (but see below for caveats).
-.ip $x
-The full name of the sender.
-.ip $z
-The home directory of the recipient.
-.ip $_
-The validated sender address.
-.ip ${bodytype}
-The message body type
-(7BIT or 8BITMIME),
-as determined from the envelope.
-.ip ${client_addr}
-The IP address of the SMTP client.
-Defined in the SMTP server only.
-.ip ${client_name}
-The host name of the SMTP client.
-Defined in the SMTP server only.
-.ip ${client_port}
-The port number of the SMTP client.
-Defined in the SMTP server only.
-.ip ${envid}
-The envelope id passed to sendmail as part of the envelope.
-.ip ${opMode}
-The current operation mode (from the
-.b \-b
-flag).
-.pp
-There are three types of dates that can be used.
-The
-.b $a
-and
-.b $b
-macros are in RFC 822 format;
-.b $a
-is the time as extracted from the
-.q Date:
-line of the message
-(if there was one),
-and
-.b $b
-is the current date and time
-(used for postmarks).
-If no
-.q Date:
-line is found in the incoming message,
-.b $a
-is set to the current time also.
-The
-.b $d
-macro is equivalent to the
-.b $b
-macro in UNIX
-(ctime)
-format.
-.pp
-The macros
-.b $w ,
-.b $j ,
-and
-.b $m
-are set to the identity of this host.
-.i Sendmail
-tries to find the fully qualified name of the host
-if at all possible;
-it does this by calling
-.i gethostname (2)
-to get the current hostname
-and then passing that to
-.i gethostbyname (3)
-which is supposed to return the canonical version of that host name.\**
-.(f
-\**For example, on some systems
-.i gethostname
-might return
-.q foo
-which would be mapped to
-.q foo.bar.com
-by
-.i gethostbyname .
-.)f
-Assuming this is successful,
-.b $j
-is set to the fully qualified name
-and
-.b $m
-is set to the domain part of the name
-(everything after the first dot).
-The
-.b $w
-macro is set to the first word
-(everything before the first dot)
-if you have a level 5 or higher configuration file;
-otherwise, it is set to the same value as
-.b $j .
-If the canonification is not successful,
-it is imperative that the config file set
-.b $j
-to the fully qualified domain name\**.
-.(f
-\**Older versions of sendmail didn't pre-define
-.b $j
-at all, so up until 8.6,
-config files
-.i always
-had to define
-.b $j .
-.)f
-.pp
-The
-.b $f
-macro is the id of the sender
-as originally determined;
-when mailing to a specific host
-the
-.b $g
-macro is set to the address of the sender
-.ul
-relative to the recipient.
-For example,
-if I send to
-.q bollard@matisse.CS.Berkeley.EDU
-from the machine
-.q vangogh.CS.Berkeley.EDU
-the
-.b $f
-macro will be
-.q eric
-and the
-.b $g
-macro will be
-.q eric@vangogh.CS.Berkeley.EDU.
-.pp
-The
-.b $x
-macro is set to the full name of the sender.
-This can be determined in several ways.
-It can be passed as flag to
-.i sendmail .
-It can be defined in the
-.sm NAME
-environment variable.
-The third choice is the value of the
-.q Full-Name:
-line in the header if it exists,
-and the fourth choice is the comment field
-of a
-.q From:
-line.
-If all of these fail,
-and if the message is being originated locally,
-the full name is looked up in the
-.i /etc/passwd
-file.
-.pp
-When sending,
-the
-.b $h ,
-.b $u ,
-and
-.b $z
-macros get set to the host, user, and home directory
-(if local)
-of the recipient.
-The first two are set from the
-.b $@
-and
-.b $:
-part of the rewriting rules, respectively.
-.pp
-The
-.b $p
-and
-.b $t
-macros are used to create unique strings
-(e.g., for the
-.q Message-Id:
-field).
-The
-.b $i
-macro is set to the queue id on this host;
-if put into the timestamp line
-it can be extremely useful for tracking messages.
-The
-.b $v
-macro is set to be the version number of
-.i sendmail ;
-this is normally put in timestamps
-and has been proven extremely useful for debugging.
-.pp
-The
-.b $c
-field is set to the
-.q "hop count,"
-i.e., the number of times this message has been processed.
-This can be determined
-by the
-.b \-h
-flag on the command line
-or by counting the timestamps in the message.
-.pp
-The
-.b $r
-and
-.b $s
-fields are set to the protocol used to communicate with
-.i sendmail
-and the sending hostname.
-They can be set together using the
-.b \-p
-command line flag or separately using the
-.b \-M
-or
-.b \-oM
-flags.
-.pp
-The
-.b $_
-is set to a validated sender host name.
-If the sender is running an RFC 1413 compliant IDENT server
-and the receiver has the IDENT protocol turned on,
-it will include the user name on that host.
-.pp
-The
-.b ${client_name} ,
-.b ${client_addr} ,
-and
-.b ${client_port}
-macros
-are set to the name, address, and port number of the SMTP client
-who is invoking
-.i sendmail
-as a server.
-These can be used in the
-.i check_*
-rulesets (using the
-.b $&
-deferred evaluation form, of course!).
-.sh 2 "C and F \*- Define Classes"
-.pp
-Classes of phrases may be defined
-to match on the left hand side of rewriting rules,
-where a
-.q phrase
-is a sequence of characters that do not contain space characters.
-For example
-a class of all local names for this site
-might be created
-so that attempts to send to oneself
-can be eliminated.
-These can either be defined directly in the configuration file
-or read in from another file.
-Classes are named as a single letter or a word in {braces}.
-Class names beginning with lower case letters
-and special characters are reserved for system use.
-Classes defined in config files may be given names
-from the set of upper case letters for short names
-or beginning with an upper case letter for long names.
-.pp
-The syntax is:
-.(b F
-.b C \c
-.i c\|phrase1
-.i phrase2...
-.br
-.b F \c
-.i c\|file
-.)b
-The first form defines the class
-.i c
-to match any of the named words.
-It is permissible to split them among multiple lines;
-for example, the two forms:
-.(b
-CHmonet ucbmonet
-.)b
-and
-.(b
-CHmonet
-CHucbmonet
-.)b
-are equivalent.
-The ``F'' form
-reads the elements of the class
-.i c
-from the named
-.i file .
-.pp
-Elements of classes can be accessed in rules using
-.b $=
-or
-.b $~ .
-The
-.b $~
-(match entries not in class)
-only matches a single word;
-multi-word entries in the class are ignored in this context.
-.pp
-Some classes have internal meaning to
-.i sendmail :
-.nr ii 0.5i
-.\".ip $=b
-.\"A set of Content-Types that will not have the newline character
-.\"translated to CR-LF before encoding into base64 MIME.
-.\"The class can have major times
-.\"(e.g.,
-.\".q image )
-.\"or full types
-.\"(such as
-.\".q application/octet-stream ).
-.\"The class is initialized with
-.\".q application/octet-stream ,
-.\".q image ,
-.\".q audio ,
-.\"and
-.\".q video .
-.ip $=e
-contains the Content-Transfer-Encodings that can be 8\(->7 bit encoded.
-It is predefined to contain
-.q 7bit ,
-.q 8bit ,
-and
-.q binary .
-.ip $=k
-set to be the same as
-.b $k ,
-that is, the UUCP node name.
-.ip $=m
-set to the set of domains by which this host is known,
-initially just
-.b $m .
-.ip $=n
-can be set to the set of MIME body types
-that can never be eight to seven bit encoded.
-It defaults to
-.q multipart/signed .
-Message types
-.q message/*
-and
-.q multipart/*
-are never encoded directly.
-Multipart messages are always handled recursively.
-The handling of message/* messages
-are controlled by class
-.b $=s .
-.ip $=q
-A set of Content-Types that will never be encoded as base64
-(if they have to be encoded, they will be encoded as quoted-printable).
-It can have primary types
-(e.g.,
-.q text )
-or full types
-(such as
-.q text/plain ).
-The class is initialized to have
-.q text/plain
-only.
-.ip $=s
-contains the set of subtypes of message that can be treated recursively.
-By default it contains only
-.q rfc822 .
-Other
-.q message/*
-types cannot be 8\(->7 bit encoded.
-If a message containing eight bit data is sent to a seven bit host,
-and that message cannot be encoded into seven bits,
-it will be stripped to 7 bits.
-.ip $=t
-set to the set of trusted users by the
-.b T
-configuration line.
-If you want to read trusted users from a file use
-.b Ft \c
-.i /file/name .
-.ip $=w
-set to be the set of all names
-this host is known by.
-This can be used to match local hostnames.
-.pp
-.i Sendmail
-can be compiled to allow a
-.i scanf (3)
-string on the
-.b F
-line.
-This lets you do simplistic parsing of text files.
-For example, to read all the user names in your system
-.i /etc/passwd
-file into a class, use
-.(b
-FL/etc/passwd %[^:]
-.)b
-which reads every line up to the first colon.
-.sh 2 "M \*- Define Mailer"
-.pp
-Programs and interfaces to mailers
-are defined in this line.
-The format is:
-.(b F
-.b M \c
-.i name ,
-{\c
-.i field =\c
-.i value \|}*
-.)b
-where
-.i name
-is the name of the mailer
-(used internally only)
-and the
-.q field=name
-pairs define attributes of the mailer.
-Fields are:
-.(b
-.ta 1i
-Path	The pathname of the mailer
-Flags	Special flags for this mailer
-Sender	Rewriting set(s) for sender addresses
-Recipient	Rewriting set(s) for recipient addresses
-Argv	An argument vector to pass to this mailer
-Eol	The end-of-line string for this mailer
-Maxsize	The maximum message length to this mailer
-Linelimit	The maximum line length in the message body
-Directory	The working directory for the mailer
-Userid	The default user and group id to run as
-Nice	The nice(2) increment for the mailer
-Charset	The default character set for 8-bit characters
-Type	The MTS type information (used for error messages)
-.)b
-Only the first character of the field name is checked.
-.pp
-The following flags may be set in the mailer description.
-Any other flags may be used freely
-to conditionally assign headers to messages
-destined for particular mailers.
-Flags marked with \(dg
-are not interpreted by the
-.i sendmail
-binary;
-these are the conventionally used to correlate to the flags portion
-of the
-.b H
-line.
-Flags marked with \(dd
-apply to the mailers for the sender address
-rather than the usual recipient mailers.
-.nr ii 4n
-.ip a
-Run Extended SMTP (ESMTP) protocol (defined in RFCs 1651, 1652, and 1653).
-This flag defaults on if the SMTP greeting message includes the word
-.q ESMTP .
-.ip A
-Look up the user part of the address in the alias database.
-Normally this is only set for local mailers.
-.ip b
-Force a blank line on the end of a message.
-This is intended to work around some stupid versions of
-/bin/mail
-that require a blank line, but do not provide it themselves.
-It would not normally be used on network mail.
-.ip c
-Do not include comments in addresses.
-This should only be used if you have to work around
-a remote mailer that gets confused by comments.
-This strips addresses of the form
-.q "Phrase <address>"
-or
-.q "address (Comment)"
-down to just
-.q address .
-.ip C\(dd
-If mail is
-.i received
-from a mailer with this flag set,
-any addresses in the header that do not have an at sign
-(\c
-.q @ )
-after being rewritten by ruleset three
-will have the
-.q @domain
-clause from the sender envelope address
-tacked on.
-This allows mail with headers of the form:
-.(b
-From: usera@hosta
-To: userb@hostb, userc
-.)b
-to be rewritten as:
-.(b
-From: usera@hosta
-To: userb@hostb, userc@hosta
-.)b
-automatically.
-However, it doesn't really work reliably.
-.ip d
-Do not include angle brackets around route-address syntax addresses.
-This is useful on mailers that are going to pass addresses to a shell
-that might interpret angle brackets as I/O redirection.
-.ip D\(dg
-This mailer wants a
-.q Date:
-header line.
-.ip e
-This mailer is expensive to connect to,
-so try to avoid connecting normally;
-any necessary connection will occur during a queue run.
-.ip E
-Escape lines beginning with
-.q From
-in the message with a `>' sign.
-.ip f
-The mailer wants a
-.b \-f
-.i from
-flag,
-but only if this is a network forward operation
-(i.e.,
-the mailer will give an error
-if the executing user
-does not have special permissions).
-.ip F\(dg
-This mailer wants a
-.q From:
-header line.
-.ip g
-Normally,
-.i sendmail
-sends internally generated email (e.g., error messages)
-using the null return address
-as required by RFC 1123.
-However, some mailers don't accept a null return address.
-If necessary,
-you can set the
-.b g
-flag to prevent
-.i sendmail
-from obeying the standards;
-error messages will be sent as from the MAILER-DAEMON
-(actually, the value of the
-.b $n
-macro).
-.ip h
-Upper case should be preserved in host names
-for this mailer.
-.ip i
-Do User Database rewriting on envelope sender address.
-.ip I
-This mailer will be speaking SMTP
-to another
-.i sendmail
-\*-
-as such it can use special protocol features.
-This option is not required
-(i.e.,
-if this option is omitted the transmission will still operate successfully,
-although perhaps not as efficiently as possible).
-.ip j
-Do User Database rewriting on recipients as well as senders.
-.ip k
-Normally when
-.i sendmail
-connects to a host via SMTP,
-it checks to make sure that this isn't accidently the same host name
-as might happen if
-.i sendmail
-is misconfigured or if a long-haul network interface is set in loopback mode.
-This flag disables the loopback check.
-It should only be used under very unusual circumstances.
-.ip K
-Currently unimplemented.
-Reserved for chunking.
-.ip l
-This mailer is local
-(i.e.,
-final delivery will be performed).
-.ip L
-Limit the line lengths as specified in RFC821.
-This deprecated option should be replaced by the
-.b L=
-mail declaration.
-For historic reasons, the
-.b L
-flag also sets the
-.b 7
-flag.
-.ip m
-This mailer can send to multiple users
-on the same host
-in one transaction.
-When a
-.b $u
-macro occurs in the
-.i argv
-part of the mailer definition,
-that field will be repeated as necessary
-for all qualifying users.
-.ip M\(dg
-This mailer wants a
-.q Message-Id:
-header line.
-.ip n
-Do not insert a UNIX-style
-.q From
-line on the front of the message.
-.ip o
-Always run as the owner of the recipient mailbox.
-Normally
-.i sendmail
-runs as the sender for locally generated mail
-or as
-.q daemon
-(actually, the user specified in the
-.b u
-option)
-when delivering network mail.
-The normal behaviour is required by most local mailers,
-which will not allow the envelope sender address
-to be set unless the mailer is running as daemon.
-This flag is ignored if the
-.b S
-flag is set.
-.ip p
-Use the route-addr style reverse-path in the SMTP
-.q "MAIL FROM:"
-command
-rather than just the return address;
-although this is required in RFC821 section 3.1,
-many hosts do not process reverse-paths properly.
-Reverse-paths are officially discouraged by RFC 1123.
-.ip P\(dg
-This mailer wants a
-.q Return-Path:
-line.
-.ip q
-When an address that resolves to this mailer is verified
-(SMTP VRFY command),
-generate 250 responses instead of 252 responses.
-This will imply that the address is local.
-.ip r
-Same as
-.b f ,
-but sends a
-.b \-r
-flag.
-.ip R
-Open SMTP connections from a
-.q secure
-port.
-Secure ports aren't
-(secure, that is)
-except on UNIX machines,
-so it is unclear that this adds anything.
-.ip s
-Strip quote characters (" and \e) off of the address
-before calling the mailer.
-.ip S
-Don't reset the userid
-before calling the mailer.
-This would be used in a secure environment
-where
-.i sendmail
-ran as root.
-This could be used to avoid forged addresses.
-If the
-.b U=
-field is also specified,
-this flag causes the user id to always be set to that user and group
-(instead of leaving it as root).
-.ip u
-Upper case should be preserved in user names
-for this mailer.
-.ip U
-This mailer wants UUCP-style
-.q From
-lines with the ugly
-.q "remote from <host>"
-on the end.
-.ip w
-The user must have a valid account on this machine,
-i.e.,
-getpwnam
-must succeed.
-If not,
-the mail is bounced.
-This is required to get
-.q \&.forward
-capability.
-.ip x\(dg
-This mailer wants a
-.q Full-Name:
-header line.
-.ip X
-This mailer want to use the hidden dot algorithm
-as specified in RFC821;
-basically,
-any line beginning with a dot
-will have an extra dot prepended
-(to be stripped at the other end).
-This insures that lines in the message containing a dot
-will not terminate the message prematurely.
-.ip 0
-Don't look up MX records for hosts sent via SMTP.
-.ip 3
-Extend the list of characters converted to =XX notation
-when converting to Quoted-Printable
-to include those that don't map cleanly between ASCII and EBCDIC.
-Useful if you have IBM mainframes on site.
-.ip 5
-If no aliases are found for this address,
-pass the address through ruleset 5 for possible alternate resolution.
-This is intended to forward the mail to an alternate delivery spot.
-.ip 7
-Strip all output to seven bits.
-This is the default if the
-.b L
-flag is set.
-Note that clearing this option is not
-sufficient to get full eight bit data passed through
-.i sendmail .
-If the
-.b 7
-option is set, this is essentially always set,
-since the eighth bit was stripped on input.
-Note that this option will only impact messages
-that didn't have 8\(->7 bit MIME conversions performed.
-.ip 8
-If set,
-it is acceptable to send eight bit data to this mailer;
-the usual attempt to do 8\(->7 bit MIME conversions will be bypassed.
-.ip 9
-If set,
-do
-.i limited
-7\(->8 bit MIME conversions.
-These conversions are limited to text/plain data.
-.ip :
-Check addresses to see if they begin
-.q :include: ;
-if they do, convert them to the
-.q *include*
-mailer.
-.ip |
-Check addresses to see if they begin with a `|';
-if they do, convert them to the
-.q prog
-mailer.
-.ip /
-Check addresses to see if they begin with a `/';
-if they do, convert them to the
-.q *file*
-mailer.
-.ip @
-Look up addresses in the user database.
-.pp
-Configuration files prior to level 6
-assume the `A', `w', `5', `:', `|', `/', and `@' options
-on the mailer named
-.q local .
-.pp
-The mailer with the special name
-.q error
-can be used to generate a user error.
-The (optional) host field is an exit status to be returned,
-and the user field is a message to be printed.
-The exit status may be numeric or one of the values
-USAGE, NOUSER, NOHOST, UNAVAILABLE, SOFTWARE, TEMPFAIL, PROTOCOL, or CONFIG
-to return the corresponding EX_ exit code,
-or an enhanced error code as described in RFC 1893,
-.ul
-Enhanced Mail System Status Codes.
-For example, the entry:
-.(b
-$#error $@ NOHOST $: Host unknown in this domain
-.)b
-on the RHS of a rule
-will cause the specified error to be generated
-and the
-.q "Host unknown"
-exit status to be returned
-if the LHS matches.
-This mailer is only functional in rulesets 0, 5,
-or one of the check_* rulesets.
-.pp
-The mailer named
-.q local
-.i must
-be defined in every configuration file.
-This is used to deliver local mail,
-and is treated specially in several ways.
-Additionally, three other mailers named
-.q prog ,
-.q *file* ,
-and
-.q *include*
-may be defined to tune the delivery of messages to programs,
-files,
-and :include: lists respectively.
-They default to:
-.(b
-Mprog, P=/bin/sh, F=lsD, A=sh \-c $u
-M*file*, P=/dev/null, F=lsDFMPEu, A=FILE
-M*include*, P=/dev/null, F=su, A=INCLUDE
-.)b
-.pp
-The Sender and Recipient rewriting sets
-may either be a simple ruleset id
-or may be two ids separated by a slash;
-if so, the first rewriting set is applied to envelope
-addresses
-and the second is applied to headers.
-.pp
-The Directory
-is actually a colon-separated path of directories to try.
-For example, the definition
-.q D=$z:/
-first tries to execute in the recipient's home directory;
-if that is not available,
-it tries to execute in the root of the filesystem.
-This is intended to be used only on the
-.q prog
-mailer,
-since some shells (such as
-.i csh )
-refuse to execute if they cannot read the home directory.
-Since the queue directory is not normally readable by unprivileged users
-.i csh
-scripts as recipients can fail.
-.pp
-The Userid
-specifies the default user and group id to run as,
-overriding the
-.b DefaultUser
-option (q.v.).
-If the
-.b S
-mailer flag is also specified,
-this is the user and group to run as in all circumstances.
-This may be given as
-.i user:group
-to set both the user and group id;
-either may be an integer or a symbolic name to be looked up
-in the
-.i passwd
-and
-.i group
-files respectively.
-If only a symbolic user name is specified,
-the group id in the
-.i passwd
-file for that user is used as the group id.
-.pp
-The Charset field
-is used when converting a message to MIME;
-this is the character set used in the
-Content-Type: header.
-If this is not set, the
-.b DefaultCharset
-option is used,
-and if that is not set, the value
-.q unknown-8bit
-is used.
-.b WARNING:
-this field applies to the sender's mailer,
-not the recipient's mailer.
-For example, if the envelope sender address
-lists an address on the local network
-and the recipient is on an external network,
-the character set will be set from the Charset= field
-for the local network mailer,
-not that of the external network mailer.
-.pp
-The Type= field
-sets the type information
-used in MIME error messages
-as defined by
-RFC 1894.
-It is actually three values separated by slashes:
-the MTA-type (that is, the description of how hosts are named),
-the address type (the description of e-mail addresses),
-and the diagnostic type (the description of error diagnostic codes).
-Each of these must be a registered value
-or begin with
-.q X\- .
-The default is
-.q dns/rfc822/smtp .
-.sh 2 "H \*- Define Header"
-.pp
-The format of the header lines that
-.i sendmail
-inserts into the message
-are defined by the
-.b H
-line.
-The syntax of this line is:
-.(b F
-.b H [\c
-.b ? \c
-.i mflags \c
-.b ? ]\c
-.i hname \c
-.b :
-.i htemplate
-.)b
-Continuation lines in this spec
-are reflected directly into the outgoing message.
-The
-.i htemplate
-is macro expanded before insertion into the message.
-If the
-.i mflags
-(surrounded by question marks)
-are specified,
-at least one of the specified flags
-must be stated in the mailer definition
-for this header to be automatically output.
-If one of these headers is in the input
-it is reflected to the output
-regardless of these flags.
-.pp
-Some headers have special semantics
-that will be described later.
-.sh 2 "O \*- Set Option"
-.pp
-There are a number of
-global
-options that
-can be set from a configuration file.
-Options are represented by full words;
-some are also representable as single characters
-for back compatibility.
-The syntax of this line is:
-.(b F
-.b O \0
-.i option \c
-.b = \c
-.i value
-.)b
-This sets option
-.i option
-to be
-.i value .
-Note that there
-.i must
-be a space between the letter `O' and the name of the option.
-An older version is:
-.(b F
-.b O \c
-.i o\|value
-.)b
-where the option
-.i o
-is a single character.
-Depending on the option,
-.i value
-may be a string, an integer,
-a boolean
-(with legal values
-.q t ,
-.q T ,
-.q f ,
-or
-.q F ;
-the default is TRUE),
-or
-a time interval.
-.pp
-The options supported (with the old, one character names in brackets) are:
-.nr ii 1i
-.ip "AliasFile=\fIspec, spec, ...\fP"
-[A]
-Specify possible alias file(s).
-Each
-.i spec
-should be in the format
-``\c
-.i class \c
-.b :
-.i file ''
-where
-.i class \c
-.b :
-is optional and defaults to ``implicit''.
-Depending on how
-.i sendmail
-is compiled, valid classes are
-.q implicit
-(search through a compiled-in list of alias file types,
-for back compatibility),
-.q hash
-(if
-.sm NEWDB
-is specified),
-.q dbm
-(if
-.sm NDBM
-is specified),
-.q stab
-(internal symbol table \*- not normally used
-unless you have no other database lookup),
-or
-.q nis
-(if
-.sm NIS
-is specified).
-If a list of
-.i spec s
-are provided,
-.i sendmail
-searches them in order.
-.ip AliasWait=\fItimeout\fP
-[a]
-If set,
-wait up to
-.i timeout
-(units default to minutes)
-for an
-.q @:@
-entry to exist in the alias database
-before starting up.
-If it does not appear in the
-.i timeout
-interval
-rebuild the database
-(if the
-.b AutoRebuildAliases
-option is also set)
-or issue a warning.
-.ip AllowBogusHELO
-[no short name]
-If set, allow HELO SMTP commands that don't include a host name.
-Setting this violates RFC 1123 section 5.2.5,
-but is necessary to interoperate with several SMTP clients.
-If there is a value, it is still checked for legitimacy.
-.ip AutoRebuildAliases
-[D]
-If set,
-rebuild the alias database if necessary and possible.
-If this option is not set,
-.i sendmail
-will never rebuild the alias database
-unless explicitly requested
-using
-.b \-bi .
-Not recommended \(em can cause thrashing.
-.ip BlankSub=\fIc\fP
-[B]
-Set the blank substitution character to
-.i c .
-Unquoted spaces in addresses are replaced by this character.
-Defaults to space (i.e., no change is made).
-.ip CheckAliases
-[n]
-Validate the RHS of aliases when rebuilding the alias database.
-.ip CheckpointInterval=\fIN\fP
-[C]
-Checkpoints the queue every
-.i N
-(default 10)
-addresses sent.
-If your system crashes during delivery to a large list,
-this prevents retransmission to any but the last
-.I N
-recipients.
-.ip ClassFactor=\fIfact\fP
-[z]
-The indicated
-.i fact or
-is multiplied by the message class
-(determined by the Precedence: field in the user header
-and the
-.b P
-lines in the configuration file)
-and subtracted from the priority.
-Thus, messages with a higher Priority: will be favored.
-Defaults to 1800.
-.ip ColonOkInAddr
-[no short name]
-If set, colons are acceptable in e-mail addresses
-(e.g.,
-.q host:user ).
-If not set, colons indicate the beginning of a RFC 822 group construct
-(\c
-.q "groupname: member1, member2, ... memberN;" ).
-Doubled colons are always acceptable
-(\c
-.q nodename::user )
-and proper route-addr nesting is understood
-(\c
-.q <@relay:user@host> ).
-Furthermore, this option defaults on if the configuration version level
-is less than 6 (for back compatibility).
-However, it must be off for full compatibility with RFC 822.
-.ip ConnectionCacheSize=\fIN\fP
-[k]
-The maximum number of open connections that will be cached at a time.
-The default is one.
-This delays closing the current connection until
-either this invocation of
-.i sendmail
-needs to connect to another host
-or it terminates.
-Setting it to zero defaults to the old behavior,
-that is, connections are closed immediately.
-Since this consumes file descriptors,
-the connection cache should be kept small:
-4 is probably a practical maximum.
-.ip ConnectionCacheTimeout=\fItimeout\fP
-[K]
-The maximum amount of time a cached connection will be permitted to idle
-without activity.
-If this time is exceeded,
-the connection is immediately closed.
-This value should be small (on the order of ten minutes).
-Before
-.i sendmail
-uses a cached connection,
-it always sends a RSET command
-to check the connection;
-if this fails, it reopens the connection.
-This keeps your end from failing if the other end times out.
-The point of this option is to be a good network neighbor
-and avoid using up excessive resources
-on the other end.
-The default is five minutes.
-.ip ConnectionRateThrottle=\fIN\fP
-[no short name]
-If set to a positive value,
-allow no more than
-.i N
-incoming daemon connections in a one second period.
-This is intended to flatten out peaks
-and allow the load average checking to cut in.
-Defaults to zero (no limits).
-.ip DaemonPortOptions=\fIoptions\fP
-[O]
-Set server SMTP options.
-The options are
-.i key=value
-pairs.
-Known keys are:
-.(b
-.ta 1i
-Port	Name/number of listening port (defaults to "smtp")
-Addr	Address mask (defaults INADDR_ANY)
-Family	Address family (defaults to INET)
-Listen	Size of listen queue (defaults to 10)
-SndBufSize	Size of TCP send buffer
-RcvBufSize	Size of TCP receive buffer
-.)b
-The
-.i Addr ess
-mask may be a numeric address in dot notation
-or a network name.
-.ip DefaultCharSet=\fIcharset\fP
-[no short name]
-When a message that has 8-bit characters but is not in MIME format
-is converted to MIME
-(see the EightBitMode option)
-a character set must be included in the Content-Type: header.
-This character set is normally set from the Charset= field
-of the mailer descriptor.
-If that is not set, the value of this option is used.
-If this option is not set, the value
-.q unknown-8bit
-is used.
-.ip DefaultUser=\fIuser:group\fP
-[u]
-Set the default userid for mailers to
-.i user:group .
-If
-.i group
-is omitted and 
-.i user
-is a user name
-(as opposed to a numeric user id)
-the default group listed in the /etc/passwd file for that user is used
-as the default group.
-Both
-.i user
-and
-.i group
-may be numeric.
-Mailers without the
-.i S
-flag in the mailer definition
-will run as this user.
-Defaults to 1:1.
-The value can also be given as a symbolic user name.\**
-.(f
-\**The old
-.b g
-option has been combined into the
-.b DefaultUser
-option.
-.)f
-.ip DeliveryMode=\fIx\fP
-[d]
-Deliver in mode
-.i x .
-Legal modes are:
-.(b
-.ta 4n
-i	Deliver interactively (synchronously)
-b	Deliver in background (asynchronously)
-q	Just queue the message (deliver during queue run)
-d	Defer delivery and all map lookups (deliver during queue run)
-.)b
-Defaults to ``b'' if no option is specified,
-``i'' if it is specified but given no argument
-(i.e., ``Od'' is equivalent to ``Odi'').
-The
-.b \-v
-command line flag sets this to
-.b i .
-.ip DialDelay=\fIsleeptime\fP
-[no short name]
-Dial-on-demand network connections can see timeouts
-if a connection is opened before the call is set up.
-If this is set to an interval and a connection times out
-on the first connection being attempted
-.i sendmail
-will sleep for this amount of time and try again.
-This should give your system time to establish the connection
-to your service provider.
-Units default to seconds, so
-.q DialDelay=5
-uses a five second delay.
-Defaults to zero
-(no retry).
-.ip DontExpandCnames
-[no short name]
-The standards say that all host addresses used in a mail message
-must be fully canonical.
-For example, if your host is named
-.q Cruft.Foo.ORG
-and also has an alias of
-.q FTP.Foo.ORG ,
-the former name must be used at all times.
-This is enforced during host name canonification
-($[ ... $] lookups).
-If this option is set, the protocols are ignored and the
-.q wrong
-thing is done.
-However, the IETF is moving toward changing this standard,
-so the behaviour may become acceptable.
-Please note that hosts downstream may still rewrite the address
-to be the true canonical name however.
-.ip DontInitGroups
-[no short name]
-If set,
-.i sendmail
-will avoid using the initgroups(3) call.
-If you are running NIS,
-this causes a sequential scan of the groups.byname map,
-which can cause your NIS server to be badly overloaded in a large domain.
-The cost of this is that the only group found for users
-will be their primary group (the one in the password file),
-which will make file access permissions somewhat more restrictive.
-Has no effect on systems that don't have group lists.
-.ip DontPruneRoutes
-[R]
-Normally,
-.i sendmail
-tries to eliminate any unnecessary explicit routes
-when sending an error message
-(as discussed in RFC 1123 \(sc 5.2.6).
-For example,
-when sending an error message to
-.(b
-<@known1,@known2,@known3:user@unknown>
-.)b
-.i sendmail
-will strip off the
-.q @known1,@known2
-in order to make the route as direct as possible.
-However, if the
-.b R
-option is set, this will be disabled,
-and the mail will be sent to the first address in the route,
-even if later addresses are known.
-This may be useful if you are caught behind a firewall.
-.ip DoubleBounceAddress=\fIerror-address\fP
-[no short name]
-If an error occurs when sending an error message,
-send the error report
-(termed a
-.q "double bounce"
-because it is an error
-.q bounce
-that occurs when trying to send another error
-.q bounce )
-to the indicated address.
-If not set, defaults to
-.q postmaster .
-.ip EightBitMode=\fIaction\fP
-[8]
-Set handling of eight-bit data.
-There are two kinds of eight-bit data:
-that declared as such using the
-.b BODY=8BITMIME
-ESMTP declaration or the
-.b \-B8BITMIME
-command line flag,
-and undeclared 8-bit data, that is,
-input that just happens to be eight bits.
-There are three basic operations that can happen:
-undeclared 8-bit data can be automatically converted to 8BITMIME,
-undeclared 8-bit data can be passed as-is without conversion to MIME
-(``just send 8''),
-and declared 8-bit data can be converted to 7-bits
-for transmission to a non-8BITMIME mailer.
-The possible
-.i action s
-are:
-.(b
-.\"  r	Reject undeclared 8-bit data;
-.\"	don't convert 8BITMIME\(->7BIT (``reject'')
-  s	Reject undeclared 8-bit data (``strict'')
-.\"	do convert 8BITMIME\(->7BIT (``strict'')
-.\"  c	Convert undeclared 8-bit data to MIME;
-.\"	don't convert 8BITMIME\(->7BIT (``convert'')
-  m	Convert undeclared 8-bit data to MIME (``mime'')
-.\"	do convert 8BITMIME\(->7BIT (``mime'')
-.\"  j	Pass undeclared 8-bit data;
-.\"	don't convert 8BITMIME\(->7BIT (``just send 8'')
-  p	Pass undeclared 8-bit data (``pass'')
-.\"	do convert 8BITMIME\(->7BIT (``pass'')
-.\"  a	Adaptive algorithm: see below
-.)b
-.\"The adaptive algorithm is to accept 8-bit data,
-.\"converting it to 8BITMIME only if the receiver understands that,
-.\"otherwise just passing it as undeclared 8-bit data;
-.\"8BITMIME\(->7BIT conversions are done.
-In all cases properly declared 8BITMIME data will be converted to 7BIT
-as needed.
-.ip ErrorHeader=\fIfile-or-message\fP
-[E]
-Prepend error messages with the indicated message.
-If it begins with a slash,
-it is assumed to be the pathname of a file
-containing a message (this is the recommended setting).
-Otherwise, it is a literal message.
-The error file might contain the name, email address, and/or phone number
-of a local postmaster who could provide assistance
-in to end users.
-If the option is missing or null,
-or if it names a file which does not exist or which is not readable,
-no message is printed.
-.ip ErrorMode=\fIx\fP
-[e]
-Dispose of errors using mode
-.i x .
-The values for
-.i x
-are:
-.(b
-p	Print error messages (default)
-q	No messages, just give exit status
-m	Mail back errors
-w	Write back errors (mail if user not logged in)
-e	Mail back errors and give zero exit stat always
-.)b
-.ip FallbackMXhost=\fIfallbackhost\fP
-[V]
-If specified, the
-.i fallbackhost
-acts like a very low priority MX
-on every host.
-This is intended to be used by sites with poor network connectivity.
-.ip ForkEachJob
-[Y]
-If set,
-deliver each job that is run from the queue in a separate process.
-Use this option if you are short of memory,
-since the default tends to consume considerable amounts of memory
-while the queue is being processed.
-.ip ForwardPath=\fIpath\fP
-[J]
-Set the path for searching for users' .forward files.
-The default is
-.q $z/.forward .
-Some sites that use the automounter may prefer to change this to
-.q /var/forward/$u
-to search a file with the same name as the user in a system directory.
-It can also be set to a sequence of paths separated by colons;
-.i sendmail
-stops at the first file it can successfully and safely open.
-For example,
-.q /var/forward/$u:$z/.forward
-will search first in /var/forward/\c
-.i username
-and then in
-.i ~username /.forward
-(but only if the first file does not exist).
-.ip HelpFile=\fIfile\fP
-[H]
-Specify the help file
-for SMTP.
-.ip HoldExpensive
-[c]
-If an outgoing mailer is marked as being expensive,
-don't connect immediately.
-This requires that queueing be compiled in,
-since it will depend on a queue run process to
-actually send the mail.
-.ip HostsFile=\fIpath\fP
-[no short name]
-The path to the hosts database,
-normally
-.q /etc/hosts .
-This option is only consulted when sendmail
-is canonifying addresses,
-and then only when
-.q files
-is in the
-.q hosts
-service switch entry.
-In particular, this file is
-.i never
-used when looking up host addresses;
-that is under the control of the system
-.i gethostbyname (3)
-routine.
-.ip HostStatusDirectory=\fIpath\fP
-[no short name]
-The location of the long term host status information.
-When set,
-information about the status of hosts
-(e.g., host down or not accepting connections)
-will be shared between all
-.i sendmail
-processes;
-normally, this information is only held within a single queue run.
-This option requires a connection cache of at least 1 to function.
-If the option begins with a leading `/',
-it is an absolute pathname;
-otherwise,
-it is relative to the mail queue directory.
-A suggested value for sites desiring persistent host status is
-.q \&.hoststat
-(i.e., a subdirectory of the queue directory).
-.ip IgnoreDots
-[i]
-Ignore dots in incoming messages.
-This is always disabled (that is, dots are always accepted)
-when reading SMTP mail.
-.ip LogLevel=\fIn\fP
-[L]
-Set the default log level to
-.i n .
-Defaults to 9.
-.ip M\fIx\|value\fP
-[no long version]
-Set the macro
-.i x
-to
-.i value .
-This is intended only for use from the command line.
-The
-.b \-M
-flag is preferred.
-.ip MatchGECOS
-[G]
-Allow fuzzy matching on the GECOS field.
-If this flag is set,
-and the usual user name lookups fail
-(that is, there is no alias with this name and a
-.i getpwnam
-fails),
-sequentially search the password file
-for a matching entry in the GECOS field.
-This also requires that MATCHGECOS
-be turned on during compilation.
-This option is not recommended.
-.ip MaxDaemonChildren=\fIN\fP
-[no short name]
-If set,
-.i sendmail
-will refuse connections when it has more than
-.i N
-children processing incoming mail.
-This does not limit the number of outgoing connections.
-If not set, there is no limit to the number of children --
-that is, the system load averaging controls this.
-.ip MaxHopCount=\fIN\fP
-[h]
-The maximum hop count.
-Messages that have been processed more than
-.i N
-times are assumed to be in a loop and are rejected.
-Defaults to 25.
-.ip MaxHostStatAge=\fIage\fP
-[no short name]
-Not yet implemented.
-This option specifies how long host status information will be retained.
-For example, if a host is found to be down,
-connections to that host will not be retried for this interval.
-The units default to minutes.
-.ip MaxMessageSize=\fIN\fP
-[no short name]
-Specify the maximum message size
-to be advertised in the ESMTP EHLO response.
-Messages larger than this will be rejected.
-.ip MaxQueueRunSize=\fIN\fP
-[no short name]
-The maximum number of jobs that will be processed
-in a single queue run.
-If not set, there is no limit on the size.
-If you have very large queues or a very short queue run interval
-this could be unstable.
-However, since the first
-.i N
-jobs in queue directory order are run (rather than the
-.i N
-highest priority jobs)
-this should be set as high as possible to avoid
-.q losing
-jobs that happen to fall late in the queue directory.
-.ip MeToo
-[m]
-Send to me too,
-even if I am in an alias expansion.
-.ip MinFreeBlocks=\fIN\fP
-[b]
-Insist on at least
-.i N
-blocks free on the filesystem that holds the queue files
-before accepting email via SMTP.
-If there is insufficient space
-.i sendmail
-gives a 452 response
-to the MAIL command.
-This invites the sender to try again later.
-.ip MinQueueAge=\fPage\fP
-[no short name]
-Don't process any queued jobs
-that have been in the queue less than the indicated time interval.
-This is intended to allow you to get responsiveness
-by processing the queue fairly frequently
-without thrashing your system by trying jobs too often.
-The default units are minutes.
-.ip MustQuoteChars=\fIs\fP
-[no short name]
-Sets the list of characters that must be quoted if used in a full name
-that is in the phrase part of a ``phrase <address>'' syntax.
-The default is ``\'.''.
-The characters ``@,;:\e()[]'' are always added to this list.
-.ip NoRecipientAction
-[no short name]
-The action to take when you receive a message that has no valid
-recipient headers (To:, Cc:, Bcc:, or Apparently-To: \(em
-the last included for back compatibility with old
-.i sendmail s).
-It can be
-.b None
-to pass the message on unmodified,
-which violates the protocol,
-.b Add-To
-to add a To: header with any recipients it can find in the envelope
-(which might expose Bcc: recipients),
-.b Add-Apparently-To
-to add an Apparently-To: header
-(this is only for back-compatibility
-and is officially deprecated),
-.b Add-To-Undisclosed
-to add a header
-.q "To: undisclosed-recipients:;"
-to make the header legal without disclosing anything,
-or
-.b Add-Bcc
-to add an empty Bcc: header.
-.ip OldStyleHeaders
-[o]
-Assume that the headers may be in old format,
-i.e.,
-spaces delimit names.
-This actually turns on
-an adaptive algorithm:
-if any recipient address contains a comma, parenthesis,
-or angle bracket,
-it will be assumed that commas already exist.
-If this flag is not on,
-only commas delimit names.
-Headers are always output with commas between the names.
-Defaults to off.
-.ip OperatorChars=\fIcharlist\fP
-[$o macro]
-The list of characters that are considered to be
-.q operators ,
-that is, characters that delimit tokens.
-All operator characters are tokens by themselves;
-sequences of non-operator characters are also tokens.
-White space characters separate tokens
-but are not tokens themselves \(em for example,
-.q AAA.BBB
-has three tokens, but
-.q "AAA BBB"
-has two.
-If not set, OperatorChars defaults to
-.q \&.\|:\|@\|[\|] ;
-additionally, the characters
-.q (\|)\|<\|>\|,\|;
-are always operators.
-.ip PostmasterCopy=\fIpostmaster\fP
-[P]
-If set,
-copies of error messages will be sent to the named
-.i postmaster .
-Only the header of the failed message is sent.
-Since most errors are user problems,
-this is probably not a good idea on large sites,
-and arguably contains all sorts of privacy violations,
-but it seems to be popular with certain operating systems vendors.
-Defaults to no postmaster copies.
-.ip PrivacyOptions=\fI\|opt,opt,...\fP
-[p]
-Set the privacy
-.i opt ions.
-``Privacy'' is really a misnomer;
-many of these are just a way of insisting on stricter adherence
-to the SMTP protocol.
-The
-.i opt ions
-can be selected from:
-.(b
-.ta \w'needvrfyhelo'u+3n
-public	Allow open access
-needmailhelo	Insist on HELO or EHLO command before MAIL
-needexpnhelo	Insist on HELO or EHLO command before EXPN
-noexpn	Disallow EXPN entirely
-needvrfyhelo	Insist on HELO or EHLO command before VRFY
-novrfy	Disallow VRFY entirely
-restrictmailq	Restrict mailq command
-restrictqrun	Restrict \-q command line flag
-noreceipts	Don't return success DSNs
-goaway	Disallow essentially all SMTP status queries
-authwarnings	Put X-Authentication-Warning: headers in messages
-.)b
-The
-.q goaway
-pseudo-flag sets all flags except
-.q restrictmailq
-and
-.q restrictqrun .
-If mailq is restricted,
-only people in the same group as the queue directory
-can print the queue.
-If queue runs are restricted,
-only root and the owner of the queue directory
-can run the queue.
-Authentication Warnings add warnings about various conditions
-that may indicate attempts to spoof the mail system,
-such as using an non-standard queue directory.
-.ip QueueDirectory=\fIdir\fP
-[Q]
-Use the named
-.i dir
-as the queue directory.
-.ip QueueFactor=\fIfactor\fP
-[q]
-Use
-.i factor
-as the multiplier in the map function
-to decide when to just queue up jobs rather than run them.
-This value is divided by the difference between the current load average
-and the load average limit
-(\c
-.b QueueLA
-option)
-to determine the maximum message priority
-that will be sent.
-Defaults to 600000.
-.ip QueueLA=\fILA\fP
-[x]
-When the system load average exceeds
-.i LA ,
-just queue messages
-(i.e., don't try to send them).
-Defaults to 8.
-.ip QueueSortOrder=\fIalgorithm\fP
-[no short name]
-Sets the
-.i algorithm
-used for sorting the queue.
-Only the first character of the value is used.
-Legal values are
-.q host
-(to order by the name of the first host name of the first recipient),
-.q time
-(to order by the submission time),
-and
-.q priority
-(to order by message priority).
-Host ordering makes better use of the connection cache,
-but may tend to process low priority messages
-that go to a single host
-over high priority messages that go to several hosts;
-it probably shouldn't be used on slow network links.
-Time ordering is almost always a bad idea,
-since it allows large, bulk mail to go out
-before smaller, personal mail,
-but may have applicability on some hosts with very fast connections.
-Priority ordering is the default.
-.ip QueueTimeout=\fItimeout\fP
-[T]
-A synonym for
-.q Timeout.queuereturn .
-Use that form instead of the
-.q QueueTimeout
-form.
-.ip ResolverOptions=\fIoptions\fP
-[I]
-Set resolver options.
-Values can be set using
-.b + \c
-.i flag
-and cleared using
-.b \- \c
-.i flag ;
-the
-.i flag s
-can be
-.q debug ,
-.q aaonly ,
-.q usevc ,
-.q primary ,
-.q igntc ,
-.q recurse ,
-.q defnames ,
-.q stayopen ,
-or
-.q dnsrch .
-The string
-.q HasWildcardMX
-(without a
-.b +
-or
-.b \- )
-can be specified to turn off matching against MX records
-when doing name canonifications.
-.b N.B.
-Prior to 8.7,
-this option indicated that the name server be responding
-in order to accept addresses.
-This has been replaced by checking to see
-if the
-.q dns
-method is listed in the service switch entry for the
-.q hosts
-service.
-.ip RunAsUser=\fIuser\fP
-[no short name]
-The
-.i user
-parameter may be a user name
-(looked up in
-.i /etc/passwd )
-or a numeric user id;
-either form can have
-.q ":group"
-attached
-(where group can be numeric or symbolic).
-If set to a non-zero (non-root) value,
-.i sendmail
-will change to this user id shortly after startup\**.
-.(f
-\**When running as a daemon,
-it changes to this user after accepting a connection
-but before reading any
-.sm SMTP
-commands.
-.)f
-This avoids a certain class of security problems.
-However, this means that all
-.q \&.forward
-and
-.q :include:
-files must be readable by the indicated
-.i user ,
-and on systems that don't support the saved uid bit properly,
-all files to be written must be writable by
-.i user
-and all programs will be executed by
-.i user .
-It is also incompatible with the
-.b SafeFileEnvironment
-option.
-In other words, it may not actually add much to security on an average system,
-and may in fact detract from security
-(because other file permissions must be loosened).
-However, it should be useful on firewalls and other
-places where users don't have accounts and the aliases file is
-well constrained.
-.ip RecipientFactor=\fIfact\fP
-[y]
-The indicated
-.i fact or
-is added to the priority (thus
-.i lowering
-the priority of the job)
-for each recipient,
-i.e., this value penalizes jobs with large numbers of recipients.
-Defaults to 30000.
-.ip RefuseLA=\fILA\fP
-[X]
-When the system load average exceeds
-.i LA ,
-refuse incoming SMTP connections.
-Defaults to 12.
-.ip RetryFactor=\fIfact\fP
-[Z]
-The
-.i fact or
-is added to the priority
-every time a job is processed.
-Thus,
-each time a job is processed,
-its priority will be decreased by the indicated value.
-In most environments this should be positive,
-since hosts that are down are all too often down for a long time.
-Defaults to 90000.
-.ip SafeFileEnvironment=\fIdir\fP
-[no short name]
-If this option is set,
-.i sendmail
-will do a
-.i chroot (2)
-call into the indicated
-.i dir ectory
-before doing any file writes.
-If the file name specified by the user begins with
-.i dir ,
-that partial path name will be stripped off before writing,
-so (for example)
-if the SafeFileEnvironment variable is set to
-.q /safe
-then aliases of
-.q /safe/logs/file
-and
-.q /logs/file
-actually indicate the same file.
-Additionally, if this option is set,
-.i sendmail
-refuses to deliver to symbolic links.
-.ip SaveFromLine
-[f]
-Save
-Unix-style
-.q From
-lines at the front of headers.
-Normally they are assumed redundant
-and discarded.
-.ip SendMIMEErrors
-[j]
-If set, send error messages in MIME format
-(see RFC1521 and RFC1344 for details).
-If disabled,
-.i sendmail
-will not return the DSN keyword in response to an EHLO
-and will not do Delivery Status Notification processing as described in
-RFC1891.
-.ip ServiceSwitchFile=\fIfilename\fP
-[no short name]
-If your host operating system has a service switch abstraction
-(e.g., /etc/nsswitch.conf on Solaris
-or /etc/svc.conf on Ultrix and DEC OSF/1)
-that service will be consulted and this option is ignored.
-Otherwise, this is the name of a file
-that provides the list of methods used to implement particular services.
-The syntax is a series of lines,
-each of which is a sequence of words.
-The first word is the service name,
-and following words are service types.
-The services that
-.i sendmail
-consults directly are
-.q aliases
-and
-.q hosts.
-Service types can be
-.q dns ,
-.q nis ,
-.q nisplus ,
-or
-.q files
-(with the caveat that the appropriate support
-must be compiled in
-before the service can be referenced).
-If ServiceSwitchFile is not specified, it defaults to /etc/service.switch.
-If that file does not exist, the default switch is:
-.(b
-aliases	files
-hosts	dns nis files
-.)b
-The default file is
-.q /etc/service.switch .
-.ip SevenBitInput
-[7]
-Strip input to seven bits for compatibility with old systems.
-This shouldn't be necessary.
-.ip SingleLineFromHeader
-[no short name]
-If set, From: lines that have embedded newlines are unwrapped
-onto one line.
-This is to get around a botch in Lotus Notes
-that apparently cannot understand legally wrapped RFC822 headers.
-.ip SingleThreadDelivery
-[no short name]
-If set, a client machine will never try to open two SMTP connections
-to a single server machine at the same time,
-even in different processes.
-That is, if another
-.i sendmail
-is already talking to some host a new
-.i sendmail
-will not open another connection.
-This property is of mixed value;
-although this reduces the load on the other machine,
-it can cause mail to be delayed
-(for example, if one
-.i sendmail
-is delivering a huge message, other
-.i sendmail s
-won't be able to send even small messages).
-Also, it requires another file descriptor
-(for the lock file)
-per connection, so you may have to reduce the
-.b ConnectionCacheSize
-option to avoid running out of per-process file descriptors.
-Requires the
-.b HostStatusDirectory
-option.
-.ip SmtpGreetingMessage=\fImessage\fP
-[$e macro]
-The message printed when the SMTP server starts up.
-Defaults to
-.q "$j Sendmail $v ready at $b".
-.ip StatusFile=\fIfile\fP
-[S]
-Log summary statistics in the named
-.i file .
-If not set,
-no summary statistics are saved.
-This file does not grow in size.
-It can be printed using the
-.i mailstats (8)
-program.
-.ip SuperSafe
-[s]
-Be super-safe when running things,
-i.e.,
-always instantiate the queue file,
-even if you are going to attempt immediate delivery.
-.i Sendmail
-always instantiates the queue file
-before returning control the client
-under any circumstances.
-This should really
-.i always
-be set.
-.ip TempFileMode=\fImode\fP
-[F]
-The file mode for queue files.
-It is interpreted in octal by default.
-Defaults to 0600.
-.ip Timeout.\fItype\fP=\|\fItimeout\fP
-[r; subsumes old T option as well]
-Set timeout values.
-The actual timeout is indicated by the
-.i type .
-The recognized timeouts and their default values, and their
-minimum values specified in RFC 1123 section 5.3.2 are:
-.(b
-.ta \w'datafinal'u+3n
-initial	wait for initial greeting message [5m, 5m]
-helo	reply to HELO or EHLO command [5m, none]
-mail	reply to MAIL command [10m, 5m]
-rcpt	reply to RCPT command [1h, 5m]
-datainit	reply to DATA command [5m, 2m]
-datablock	data block read [1h, 3m]
-datafinal	reply to final ``.'' in data [1h, 10m]
-rset	reply to RSET command [5m, none]
-quit	reply to QUIT command [2m, none]
-misc	reply to NOOP and VERB commands [2m, none]
-ident	IDENT protocol timeout [30s, none]
-fileopen\(dg	timeout on opening .forward and :include: files [60s, none]
-command\(dg	command read [1h, 5m]
-queuereturn\(dg	how long until a message is returned [5d, 5d]
-queuewarn\(dg	how long until a warning is sent [none, none]
-hoststatus\(dg	how long until host status is ``stale'' [30m, none]
-.)b
-All but those marked with a dagger (\(dg)
-apply to client SMTP.
-If the message is submitted using the
-.sm NOTIFY
-.sm SMTP
-extension,
-warning messages will only be sent if
-.sm NOTIFY=DELAY
-is specified.
-The queuereturn and queuewarn timeouts
-can be further qualified with a tag based on the Precedence: field
-in the message;
-they must be one of
-.q urgent
-(indicating a positive non-zero precedence)
-.q normal
-(indicating a zero precedence), or
-.q non-urgent
-(indicating negative precedences).
-For example, setting
-.q Timeout.queuewarn.urgent=1h
-sets the warning timeout for urgent messages only
-to one hour.
-The default if no precedence is indicated
-is to set the timeout for all precedences.
-.ip TimeZoneSpec=\fItzinfo\fP
-[t]
-Set the local time zone info to
-.i tzinfo
-\*- for example,
-.q PST8PDT .
-Actually, if this is not set,
-the TZ environment variable is cleared (so the system default is used);
-if set but null, the user's TZ variable is used,
-and if set and non-null the TZ variable is set to this value.
-.ip TryNullMXList
-[w]
-If this system is the
-.q best
-(that is, lowest preference)
-MX for a given host,
-its configuration rules should normally detect this situation
-and treat that condition specially
-by forwarding the mail to a UUCP feed,
-treating it as local,
-or whatever.
-However, in some cases (such as Internet firewalls)
-you may want to try to connect directly to that host
-as though it had no MX records at all.
-Setting this option causes
-.i sendmail
-to try this.
-The downside is that errors in your configuration
-are likely to be diagnosed as
-.q "host unknown"
-or
-.q "message timed out"
-instead of something more meaningful.
-This option is disrecommended.
-.ip UnixFromLine=\fIfromline\fP
-[$l macro]
-Defines the format used when
-.i sendmail
-must add a UNIX-style From_ line
-(that is, a line beginning
-.q From<space>user ).
-Defaults to
-.q "From $g  $d" .
-Don't change this unless your system uses a different UNIX mailbox format
-(very unlikely).
-.ip UnsafeGroupWrites
-[no short name]
-If set,
-:include: and .forward files that are group writable are considered
-.q unsafe ,
-that is,
-they cannot reference programs or write directly to files.
-World writable :include: and .forward files
-are always unsafe..
-.ip UseErrorsTo
-[l]
-If there is an
-.q Errors-To:
-header, send error messages to the addresses listed there.
-They normally go to the envelope sender.
-Use of this option causes
-.i sendmail
-to violate RFC 1123.
-This option is disrecommended and deprecated.
-.ip UserDatabaseSpec=\fIudbspec\fP
-[U]
-The user database specification.
-.ip UserSubmission
-[no short name]
-This is an initial submission directly from a Mail User Agent.
-This can be set in the configuration file if you have
-MUAs that don't pass the
-.b \-U
-flag or use the
-XUSR
-ESMTP extension,
-but some relayed mail may get inappropriately rewritten if you do.
-.ip Verbose
-[v]
-Run in verbose mode.
-If this is set,
-.i sendmail
-adjusts options
-.b HoldExpensive
-(old
-.b c )
-and
-.b DeliveryMode
-(old
-.b d )
-so that all mail is delivered completely
-in a single job
-so that you can see the entire delivery process.
-Option
-.b Verbose
-should
-.i never
-be set in the configuration file;
-it is intended for command line use only.
-.lp
-All options can be specified on the command line using the
-\-O or \-o flag,
-but most will cause
-.i sendmail
-to relinquish its setuid permissions.
-The options that will not cause this are
-MinFreeBlocks [b],
-DeliveryMode [d],
-ErrorMode [e],
-IgnoreDots [i],
-LogLevel [L],
-MeToo [m],
-OldStyleHeaders [o],
-PrivacyOptions [p],
-Timeouts [r],
-SuperSafe [s],
-Verbose [v],
-CheckpointInterval [C],
-and
-SevenBitInput [7].
-Also, M (define macro) when defining the r or s macros
-is also considered
-.q safe .
-.sh 2 "P \*- Precedence Definitions"
-.pp
-Values for the
-.q "Precedence:"
-field may be defined using the
-.b P
-control line.
-The syntax of this field is:
-.(b
-\fBP\fP\fIname\fP\fB=\fP\fInum\fP
-.)b
-When the
-.i name
-is found in a
-.q Precedence:
-field,
-the message class is set to
-.i num .
-Higher numbers mean higher precedence.
-Numbers less than zero
-have the special property
-that if an error occurs during processing
-the body of the message will not be returned;
-this is expected to be used for
-.q "bulk"
-mail such as through mailing lists.
-The default precedence is zero.
-For example,
-our list of precedences is:
-.(b
-Pfirst-class=0
-Pspecial-delivery=100
-Plist=\-30
-Pbulk=\-60
-Pjunk=\-100
-.)b
-People writing mailing list exploders
-are encouraged to use
-.q "Precedence: list" .
-Older versions of
-.i sendmail
-(which discarded all error returns for negative precedences)
-didn't recognize this name, giving it a default precedence of zero.
-This allows list maintainers to see error returns
-on both old and new versions of
-.i sendmail .
-.sh 2 "V \*- Configuration Version Level"
-.pp
-To provide compatibility with old configuration files,
-the
-.b V
-line has been added to define some very basic semantics
-of the configuration file.
-These are not intended to be long term supports;
-rather, they describe compatibility features
-which will probably be removed in future releases.
-.pp
-.b N.B.:
-these version
-.i levels
-have nothing
-to do with the version
-.i number
-on the files.
-For example,
-as of this writing
-version 8 config files
-(specifically, 8.7)
-used version level 6 configurations.
-.pp
-.q Old
-configuration files are defined as version level one.
-Version level two files make the following changes:
-.np
-Host name canonification ($[ ... $])
-appends a dot if the name is recognized;
-this gives the config file a way of finding out if anything matched.
-(Actually, this just initializes the
-.q host
-map with the
-.q \-a.
-flag \*- you can reset it to anything you prefer
-by declaring the map explicitly.)
-.np
-Default host name extension is consistent throughout processing;
-version level one configurations turned off domain extension
-(that is, adding the local domain name)
-during certain points in processing.
-Version level two configurations are expected to include a trailing dot
-to indicate that the name is already canonical.
-.np
-Local names that are not aliases
-are passed through a new distinguished ruleset five;
-this can be used to append a local relay.
-This behaviour can be prevented by resolving the local name
-with an initial `@'.
-That is, something that resolves to a local mailer and a user name of
-.q vikki
-will be passed through ruleset five,
-but a user name of
-.q @vikki
-will have the `@' stripped,
-will not be passed through ruleset five,
-but will otherwise be treated the same as the prior example.
-The expectation is that this might be used to implement a policy
-where mail sent to
-.q vikki
-was handled by a central hub,
-but mail sent to
-.q vikki@localhost
-was delivered directly.
-.pp
-Version level three files
-allow # initiated comments on all lines.
-Exceptions are backslash escaped # marks
-and the $# syntax.
-.pp
-Version level four configurations
-are completely equivalent to level three
-for historical reasons.
-.pp
-Version level five configuration files
-change the default definition of
-.b $w
-to be just the first component of the hostname.
-.pp
-Version level six configuration files
-change many of the local processing options
-(such as aliasing and matching the beginning of the address for
-`|' characters)
-to be mailer flags;
-this allows fine-grained control over the special local processing.
-Level six configuration files may also use long option names.
-The
-.b ColonOkInAddr
-option (to allow colons in the local-part of addresses)
-defaults
-.b on
-for lower numbered configuration files;
-the configuration file requires some additional intelligence
-to properly handle the RFC 822 group construct.
-.pp
-The
-.b V
-line may have an optional
-.b / \c
-.i vendor
-to indicate that this configuration file uses modifications
-specific to a particular vendor\**.
-.(f
-\**And of course, vendors are encouraged to add themselves
-to the list of recognized vendors by editing the routine
-.i setvendor
-in
-.i conf.c .
-Please send e-mail to sendmail@Sendmail.ORG
-to register your vendor dialect.
-.)f
-You may use
-.q /Berkeley
-to emphasize that this configuration file
-uses the Berkeley dialect of
-.i sendmail .
-.sh 2 "K \*- Key File Declaration"
-.pp
-Special maps can be defined using the line:
-.(b
-Kmapname mapclass arguments
-.)b
-The
-.i mapname
-is the handle by which this map is referenced in the rewriting rules.
-The
-.i mapclass
-is the name of a type of map;
-these are compiled in to
-.i sendmail .
-The
-.i arguments
-are interpreted depending on the class;
-typically,
-there would be a single argument naming the file containing the map.
-.pp
-Maps are referenced using the syntax:
-.(b
-$( \fImap\fP \fIkey\fP $@ \fIarguments\fP $: \fIdefault\fP $)
-.)b
-where either or both of the
-.i arguments
-or
-.i default
-portion may be omitted.
-The
-.i "$@ arguments"
-may appear more than once.
-The indicated
-.i key
-and
-.i arguments
-are passed to the appropriate mapping function.
-If it returns a value, it replaces the input.
-If it does not return a value and the
-.i default
-is specified, the
-.i default
-replaces the input.
-Otherwise, the input is unchanged.
-.pp
-The
-.i arguments
-are passed to the map for arbitrary use.
-Most map classes can interpolate these arguments
-into their values using the syntax
-.q %\fIn\fP
-(where
-.i n
-is a digit)
-to indicate the corresponding
-.i argument .
-Argument
-.q %0
-indicates the database key.
-For example, the rule
-.(b
-.ta 1.5i
-R$\- ! $+	$: $(uucp $1 $@ $2 $: %1 @ %0 . UUCP $)
-.)b
-Looks up the UUCP name in a (user defined) UUCP map;
-if not found it turns it into
-.q \&.UUCP
-form.
-The database might contain records like:
-.(b
-decvax	%1@%0.DEC.COM
-research	%1@%0.ATT.COM
-.)b
-Note that
-.i default
-clauses never do this mapping.
-.pp
-The built in map with both name and class
-.q host
-is the host name canonicalization lookup.
-Thus,
-the syntax:
-.(b
-$(host \fIhostname\fP$)
-.)b
-is equivalent to:
-.(b
-$[\fIhostname\fP$]
-.)b
-.pp
-There are many defined classes.
-.ip dbm
-Database lookups using the ndbm(3) library.
-.i Sendmail
-must be compiled with
-.b NDBM
-defined.
-.ip btree
-Database lookups using the btree interface to the Berkeley db(3) library.
-.i Sendmail
-must be compiled with
-.b NEWDB
-defined.
-.ip hash
-Database lookups using the hash interface to the Berkeley db(3) library.
-.i Sendmail
-must be compiled with
-.b NEWDB
-defined.
-.ip nis
-NIS lookups.
-.i Sendmail
-must be compiled with
-.b NIS
-defined.
-.ip nisplus
-NIS+ lookups.
-.i Sendmail
-must be compiled with
-.b NISPLUS
-defined.
-The argument is the name of the table to use for lookups,
-and the
-.b \-k
-and
-.b \-v
-flags may be used to set the key and value columns respectively.
-.ip hesiod
-Hesiod lookups.
-.i Sendmail
-must be compiled with
-.b HESIOD
-defined.
-.ip ldapx
-LDAP X500 directory lookups.
-.i Sendmail 
-must be compiled with
-.b LDAPMAP
-defined.
-The map supports most of the standard arguments
-and most of the command line arguments of the
-.i ldapsearch
-program. 
-.ip netinfo
-NeXT NetInfo lookups.
-.i Sendmail
-must be compiled with
-.b NETINFO
-defined.
-.ip text
-Text file lookups.
-The format of the text file is defined by the
-.b \-k
-(key field number),
-.b \-v
-(value field number),
-and
-.b \-z
-(field delimiter)
-flags.
-.ip stab
-Internal symbol table lookups.
-Used internally for aliasing.
-.ip implicit
-Really should be called
-.q alias
-\(em this is used to get the default lookups
-for alias files,
-and is the default if no class is specified for alias files.
-.ip user
-Looks up users using
-.i getpwnam (3).
-The
-.b \-v
-flag can be used to specify the name of the field to return
-(although this is normally used only to check the existence
-of a user).
-.ip host
-Canonifies host domain names.
-Given a host name it calls the name server
-to find the canonical name for that host.
-.ip sequence
-The arguments on the `K' line are a list of maps;
-the resulting map searches the argument maps in order
-until it finds a match for the indicated key.
-For example, if the key definition is:
-.(b
-Kmap1 ...
-Kmap2 ...
-Kseqmap sequence map1 map2
-.)b
-then a lookup against
-.q seqmap
-first does a lookup in map1.
-If that is found, it returns immediately.
-Otherwise, the same key is used for map2.
-.ip switch
-Much like the
-.q sequence
-map except that the order of maps is determined by the service switch.
-The argument is the name of the service to be looked up;
-the values from the service switch are appended to the map name
-to create new map names.
-For example, consider the key definition:
-.(b
-Kali switch aliases
-.)b
-together with the service switch entry:
-.(b
-aliases	nis files
-.)b
-This causes a query against the map
-.q ali
-to search maps named
-.q ali.nis
-and
-.q ali.files
-in that order.
-.ip dequote
-Strip double quotes (") from a name.
-It does not strip backslashes,
-and will not strip quotes if the resulting string
-would contain unscannable syntax
-(that is, basic errors like unbalanced angle brackets;
-more sophisticated errors such as unknown hosts are not checked).
-The intent is for use when trying to accept mail from systems such as
-DECnet
-that routinely quote odd syntax such as
-.(b
-"49ers::ubell"
-.)b
-A typical usage is probably something like:
-.(b
-Kdequote dequote
-
-\&...
-
-R$\-	$: $(dequote $1 $)
-R$\- $+	$: $>3 $1 $2
-.)b
-Care must be taken to prevent unexpected results;
-for example,
-.(b
-"|someprogram < input > output"
-.)b
-will have quotes stripped,
-but the result is probably not what you had in mind.
-Fortunately these cases are rare.
-.pp
-Most of these accept as arguments the same optional flags
-and a filename
-(or a mapname for NIS;
-the filename is the root of the database path,
-so that
-.q .db
-or some other extension appropriate for the database type
-will be added to get the actual database name).
-Known flags are:
-.ip "\-o"
-Indicates that this map is optional \*- that is,
-if it cannot be opened,
-no error is produced,
-and
-.i sendmail
-will behave as if the map existed but was empty.
-.ip "\-N, \-O"
-If neither
-.b \-N
-or
-.b \-O
-are specified,
-.i sendmail
-uses an adaptive algorithm to decide whether or not to look for null bytes
-on the end of keys.
-It starts by trying both;
-if it finds any key with a null byte it never tries again without a null byte
-and vice versa.
-If
-.b \-N
-is specified it never tries without a null byte and
-if
-.b \-O
-is specified it never tries with a null byte.
-Setting one of
-these can speed matches but are never necessary.
-If both
-.b \-N
-and
-.b \-O
-are specified,
-.i sendmail
-will never try any matches at all \(em
-that is, everything will appear to fail.
-.ip "\-a\fIx\fP"
-Append the string
-.i x
-on successful matches.
-For example, the default
-.i host
-map appends a dot on successful matches.
-.ip "\-f"
-Do not fold upper to lower case before looking up the key.
-.ip "\-m"
-Match only (without replacing the value).
-If you only care about the existence of a key and not the value
-(as you might when searching the NIS map
-.q hosts.byname
-for example),
-this flag prevents the map from substituting the value.
-However,
-The \-a argument is still appended on a match,
-and the default is still taken if the match fails.
-.ip "\-k\fIkeycol\fP"
-The key column name (for NIS+) or number
-(for text lookups).
-For LDAP maps this is a filter string
-passed to printf with a %s where the string to be
-.q "mapped"
-is inserted. 
-.ip "\-v\fIvalcol\fP"
-The value column name (for NIS+) or number
-(for text lookups).
-For LDAP maps this is the name of the
-attribute to be returned.
-.ip "\-z\fIdelim\fP"
-The column delimiter (for text lookups).
-It can be a single character or one of the special strings
-.q \|\en
-or
-.q \|\et
-to indicate newline or tab respectively.
-If omitted entirely,
-the column separator is any sequence of whitespace.
-.ip "\-t"
-Normally, when a map attempts to do a lookup
-and the server fails
-(e.g.,
-.i sendmail
-couldn't contact any name server;
-this is
-.i not
-the same as an entry not being found in the map),
-the message being processed is queued for future processing.
-The
-.b \-t
-flag turns off this behaviour,
-letting the temporary failure (server down)
-act as though it were a permanent failure (entry not found).
-It is particularly useful for DNS lookups,
-where someone else's misconfigured name server can cause problems
-on your machine.
-However, care must be taken to ensure that you don't bounce mail
-that would be resolved correctly if you tried again.
-A common strategy is to forward such mail
-to another, possibly better connected, mail server.
-.ip "\-s\fIspacesub\fP
-For the dequote map only,
-the character to use to replace space characters
-after a successful dequote.
-.pp
-The
-.i dbm
-map appends the strings
-.q \&.pag
-and
-.q \&.dir
-to the given filename;
-the two
-.i db -based
-maps append
-.q \&.db .
-For example, the map specification
-.(b
-Kuucp dbm \-o \-N /usr/lib/uucpmap
-.)b
-specifies an optional map named
-.q uucp
-of class
-.q dbm ;
-it always has null bytes at the end of every string,
-and the data is located in
-/usr/lib/uucpmap.{dir,pag}.
-.pp
-The program
-.i makemap (8)
-can be used to build any of the three database-oriented maps.
-It takes the following flags:
-.ip \-f
-Do not fold upper to lower case in the map.
-.ip \-N
-Include null bytes in keys.
-.ip \-o
-Append to an existing (old) file.
-.ip \-r
-Allow replacement of existing keys;
-normally, re-inserting an existing key is an error.
-.ip \-v
-Print what is happening.
-.lp
-The
-.i sendmail
-daemon does not have to be restarted to read the new maps
-as long as you change them in place;
-file locking is used so that the maps won't be read
-while they are being updated.\**
-.(f
-\**That is, don't create new maps and then use
-.i mv (1)
-to move them into place.
-Since the maps are already open
-the new maps will never be seen.
-.)f
-.pp
-New classes can be added in the routine
-.b setupmaps
-in file
-.b conf.c .
-.sh 2 "The User Database"
-.pp
-If you have a version of
-.i sendmail
-with the user database package
-compiled in,
-the handling of sender and recipient addresses
-is modified.
-.pp
-The location of this database is controlled with the
-.b UserDatabaseSpec
-option.
-.sh 3 "Structure of the user database"
-.pp
-The database is a sorted (BTree-based) structure.
-User records are stored with the key:
-.(b
-\fIuser-name\fP\fB:\fP\fIfield-name\fP
-.)b
-The sorted database format ensures that user records are clustered together.
-Meta-information is always stored with a leading colon.
-.pp
-Field names define both the syntax and semantics of the value.
-Defined fields include:
-.nr ii 1i
-.ip maildrop
-The delivery address for this user.
-There may be multiple values of this record.
-In particular,
-mailing lists will have one
-.i maildrop
-record for each user on the list.
-.ip "mailname"
-The outgoing mailname for this user.
-For each outgoing name,
-there should be an appropriate
-.i maildrop
-record for that name to allow return mail.
-See also
-.i :default:mailname .
-.ip mailsender
-Changes any mail sent to this address to have the indicated envelope sender.
-This is intended for mailing lists,
-and will normally be the name of an appropriate -request address.
-It is very similar to the owner-\c
-.i list
-syntax in the alias file.
-.ip fullname
-The full name of the user.
-.ip office-address
-The office address for this user.
-.ip office-phone
-The office phone number for this user.
-.ip office-fax
-The office FAX number for this user.
-.ip home-address
-The home address for this user.
-.ip home-phone
-The home phone number for this user.
-.ip home-fax
-The home FAX number for this user.
-.ip project
-A (short) description of the project this person is affiliated with.
-In the University this is often just the name of their graduate advisor.
-.ip plan
-A pointer to a file from which plan information can be gathered.
-.pp
-As of this writing,
-only a few of these fields are actually being used by
-.i sendmail :
-.i maildrop
-and
-.i mailname .
-A
-.i finger
-program that uses the other fields is planned.
-.sh 3 "User database semantics"
-.pp
-When the rewriting rules submit an address to the local mailer,
-the user name is passed through the alias file.
-If no alias is found (or if the alias points back to the same address),
-the name (with
-.q :maildrop
-appended)
-is then used as a key in the user database.
-If no match occurs (or if the maildrop points at the same address),
-forwarding is tried.
-.pp
-If the first token of the user name returned by ruleset 0
-is an
-.q @
-sign, the user database lookup is skipped.
-The intent is that the user database will act as a set of defaults
-for a cluster (in our case, the Computer Science Division);
-mail sent to a specific machine should ignore these defaults.
-.pp
-When mail is sent,
-the name of the sending user is looked up in the database.
-If that user has a
-.q mailname
-record,
-the value of that record is used as their outgoing name.
-For example, I might have a record:
-.(b
-eric:mailname	Eric.Allman@CS.Berkeley.EDU
-.)b
-This would cause my outgoing mail to be sent as Eric.Allman.
-.pp
-If a
-.q maildrop
-is found for the user,
-but no corresponding
-.q mailname
-record exists,
-the record
-.q :default:mailname
-is consulted.
-If present, this is the name of a host to override the local host.
-For example, in our case we would set it to
-.q CS.Berkeley.EDU .
-The effect is that anyone known in the database
-gets their outgoing mail stamped as
-.q user@CS.Berkeley.EDU ,
-but people not listed in the database use the local hostname.
-.sh 3 "Creating the database\**"
-.(f
-\**These instructions are known to be incomplete.
-A future version of the user database is planned
-including things such as finger service \*- and good documentation.
-.)f
-.pp
-The user database is built from a text file
-using the
-.i makemap
-utility
-(in the distribution in the makemap subdirectory).
-The text file is a series of lines corresponding to userdb records;
-each line has a key and a value separated by white space.
-The key is always in the format described above \*-
-for example:
-.(b
-eric:maildrop
-.)b
-This file is normally installed in a system directory;
-for example, it might be called
-.i /etc/userdb .
-To make the database version of the map, run the program:
-.(b
-makemap btree /etc/userdb.db < /etc/userdb
-.)b
-Then create a config file that uses this.
-For example, using the V8 M4 configuration, include the
-following line in your .mc file:
-.(b
-define(\`confUSERDB_SPEC\', /etc/userdb.db)
-.)b
-.sh 1 "OTHER CONFIGURATION"
-.pp
-There are some configuration changes that can be made by
-recompiling
-.i sendmail .
-This section describes what changes can be made
-and what has to be modified to make them.
-In most cases this should be unnecessary
-unless you are porting
-.i sendmail
-to a new environment.
-.sh 2 "Parameters in src/Makefile"
-.pp
-These parameters are intended to describe the compilation environment,
-not site policy,
-and should normally be defined in src/Makefile.
-.ip NDBM
-If set,
-the new version of the DBM library
-that allows multiple databases will be used.
-If neither NDBM nor NEWDB are set,
-a much less efficient method of alias lookup is used.
-.ip NEWDB
-If set, use the new database package from Berkeley (from 4.4BSD).
-This package is substantially faster than DBM or NDBM.
-If NEWDB and NDBM are both set,
-.i sendmail
-will read DBM files,
-but will create and use NEWDB files.
-.ip NIS
-Include support for NIS.
-If set together with
-.i both
-NEWDB and NDBM,
-.i sendmail
-will create both DBM and NEWDB files if and only if
-an alias file includes the substring
-.q /yp/
-in the name.
-This is intended for compatibility with Sun Microsystems'
-.i mkalias
-program used on YP masters.
-.ip NISPLUS
-Compile in support for NIS+.
-.ip NETINFO
-Compile in support for NetInfo (NeXT stations).
-.ip LDAPMAP
-Compile in support for LDAP X500 queries.
-Requires libldap and liblber
-from the Umich LDAP 3.2 or 3.3 release. 
-.ip HESIOD
-Compile in support for Hesiod.
-.ip _PATH_SENDMAILCF
-The pathname of the sendmail.cf file.
-.ip _PATH_SENDMAILPID
-The pathname of the sendmail.pid file.
-.pp
-There are also several compilation flags to indicate the environment
-such as
-.q _AIX3
-and
-.q _SCO_unix_ .
-See the READ_ME
-file for the latest scoop on these flags.
-.sh 2 "Parameters in src/conf.h"
-.pp
-Parameters and compilation options
-are defined in conf.h.
-Most of these need not normally be tweaked;
-common parameters are all in sendmail.cf.
-However, the sizes of certain primitive vectors, etc.,
-are included in this file.
-The numbers following the parameters
-are their default value.
-.pp
-This document is not the best source of information
-for compilation flags in conf.h \(em
-see src/READ_ME or src/conf.h itself.
-.nr ii 1.2i
-.ip "MAXLINE [2048]"
-The maximum line length of any input line.
-If message lines exceed this length
-they will still be processed correctly;
-however, header lines,
-configuration file lines,
-alias lines,
-etc.,
-must fit within this limit.
-.ip "MAXNAME [256]"
-The maximum length of any name,
-such as a host or a user name.
-.ip "MAXPV [40]"
-The maximum number of parameters to any mailer.
-This limits the number of recipients that may be passed in one transaction.
-It can be set to any arbitrary number above about 10,
-since
-.i sendmail
-will break up a delivery into smaller batches as needed.
-A higher number may reduce load on your system, however.
-.ip "MAXATOM [100]"
-The maximum number of atoms
-(tokens)
-in a single address.
-For example,
-the address
-.q "eric@CS.Berkeley.EDU"
-is seven atoms.
-.ip "MAXMAILERS [25]"
-The maximum number of mailers that may be defined
-in the configuration file.
-.ip "MAXRWSETS [200]"
-The maximum number of rewriting sets
-that may be defined.
-The first half of these are reserved for numeric specification
-(e.g., ``S92''),
-while the upper half are reserved for auto-numbering
-(e.g., ``Sfoo'').
-Thus, with a value of 200 an attempt to use ``S99'' will succeed,
-but ``S100'' will fail.
-.ip "MAXPRIORITIES [25]"
-The maximum number of values for the
-.q Precedence:
-field that may be defined
-(using the
-.b P
-line in sendmail.cf).
-.ip "MAXUSERENVIRON [100]"
-The maximum number of items in the user environment
-that will be passed to subordinate mailers.
-.ip "MAXMXHOSTS [100]"
-The maximum number of MX records we will accept for any single host.
-.ip "MAXALIASDB [12]"
-The maximum number of alias databases that can be open at any time.
-Note that there may also be an open file limit.
-.ip "MAXMAPSTACK [12]"
-The maximum number of maps that may be "stacked" in a
-.b sequence
-class map.
-.ip "MAXMIMEARGS [20]"
-The maximum number of arguments in a MIME Content-Type: header;
-additional arguments will be ignored.
-.ip "MAXMIMENESTING [20]"
-The maximum depth to which MIME messages may be nested
-(that is, nested Message or Multipart documents;
-this does not limit the number of components in a single Multipart document).
-.lp
-A number of other compilation options exist.
-These specify whether or not specific code should be compiled in.
-Ones marked with \(dg
-are 0/1 valued.
-.nr ii 1.2i
-.ip NETINET\(dg
-If set,
-support for Internet protocol networking is compiled in.
-Previous versions of
-.i sendmail
-referred to this as
-.sm DAEMON ;
-this old usage is now incorrect.
-Defaults on;
-turn it off in the Makefile
-if your system doesn't support the Internet protocols.
-.ip NETISO\(dg
-If set,
-support for ISO protocol networking is compiled in
-(it may be appropriate to #define this in the Makefile instead of conf.h).
-.ip LOG
-If set,
-the
-.i syslog
-routine in use at some sites is used.
-This makes an informational log record
-for each message processed,
-and makes a higher priority log record
-for internal system errors.
-.b "STRONGLY RECOMMENDED"
-\(em if you want no logging, turn it off in the configuration file.
-.ip MATCHGECOS\(dg
-Compile in the code to do ``fuzzy matching'' on the GECOS field
-in /etc/passwd.
-This also requires that the
-.b MatchGECOS
-option be turned on.
-.ip NAMED_BIND\(dg
-Compile in code to use the
-Berkeley Internet Name Domain (BIND) server
-to resolve TCP/IP host names.
-.ip NOTUNIX
-If you are using a non-UNIX mail format,
-you can set this flag to turn off special processing
-of UNIX-style
-.q "From "
-lines.
-.ip QUEUE\(dg
-This flag should be set to compile in the queueing code.
-If this is not set,
-mailers must accept the mail immediately
-or it will be returned to the sender.
-.ip SMTP\(dg
-If set,
-the code to handle user and server SMTP will be compiled in.
-This is only necessary if your machine has some mailer
-that speaks SMTP
-(this means most machines everywhere).
-.ip USERDB\(dg
-Include the
-.b experimental
-Berkeley user information database package.
-This adds a new level of local name expansion
-between aliasing and forwarding.
-It also uses the NEWDB package.
-This may change in future releases.
-.lp
-The following options are normally turned on
-in per-operating-system clauses in conf.h.
-.ip IDENTPROTO\(dg
-Compile in the IDENT protocol as defined in RFC 1413.
-This defaults on for all systems except Ultrix,
-which apparently has the interesting
-.q feature
-that when it receives a
-.q "host unreachable"
-message it closes all open connections to that host.
-Since some firewall gateways send this error code
-when you access an unauthorized port (such as 113, used by IDENT),
-Ultrix cannot receive email from such hosts.
-.ip SYSTEM5
-Set all of the compilation parameters appropriate for System V.
-.ip HASFLOCK\(dg
-Use Berkeley-style
-.b flock
-instead of System V
-.b lockf
-to do file locking.
-Due to the highly unusual semantics of locks
-across forks in
-.b lockf ,
-this should always be used if at all possible.
-.ip HASINITGROUPS
-Set this if your system has the
-.i initgroups()
-call
-(if you have multiple group support).
-This is the default if SYSTEM5 is
-.i not
-defined or if you are on HPUX.
-.ip HASUNAME
-Set this if you have the
-.i uname (2)
-system call (or corresponding library routine).
-Set by default if
-SYSTEM5
-is set.
-.ip HASGETDTABLESIZE
-Set this if you have the
-.i getdtablesize (2)
-system call.
-.ip HASWAITPID
-Set this if you have the
-.i haswaitpid (2)
-system call.
-.ip SFS_TYPE
-The mechanism that can be used to get file system capacity information.
-The values can be one of
-SFS_USTAT (use the ustat(2) syscall),
-SFS_4ARGS (use the four argument statfs(2) syscall),
-SFS_VFS (use the two argument statfs(2) syscall including <sys/vfs.h>),
-SFS_MOUNT (use the two argument statfs(2) syscall including <sys/mount.h>),
-SFS_STATFS (use the two argument statfs(2) syscall including <sys/statfs.h>),
-SFS_STATVFS (use the two argument statfs(2) syscall including <sys/statvfs.h>),
-or
-SFS_NONE (no way to get this information).
-.ip LA_TYPE
-The load average type.
-Details are described below.
-.lp
-The are several built-in ways of computing the load average.
-.i Sendmail
-tries to auto-configure them based on imperfect guesses;
-you can select one using the
-.i cc
-option
-.b \-DLA_TYPE= \c
-.i type ,
-where
-.i type
-is:
-.ip LA_INT
-The kernel stores the load average in the kernel as an array of long integers.
-The actual values are scaled by a factor FSCALE
-(default 256).
-.ip LA_SHORT
-The kernel stores the load average in the kernel as an array of short integers.
-The actual values are scaled by a factor FSCALE
-(default 256).
-.ip LA_FLOAT
-The kernel stores the load average in the kernel as an array of
-double precision floats.
-.ip LA_MACH
-Use MACH-style load averages.
-.ip LA_SUBR
-Call the
-.i getloadavg
-routine to get the load average as an array of doubles.
-.ip LA_ZERO
-Always return zero as the load average.
-This is the fallback case.
-.lp
-If type
-.sm LA_INT ,
-.sm LA_SHORT ,
-or
-.sm LA_FLOAT
-is specified,
-you may also need to specify
-.sm _PATH_UNIX
-(the path to your system binary)
-and
-.sm LA_AVENRUN
-(the name of the variable containing the load average in the kernel;
-usually
-.q _avenrun
-or
-.q avenrun ).
-.sh 2 "Configuration in src/conf.c"
-.pp
-The following changes can be made in conf.c.
-.sh 3 "Built-in Header Semantics"
-.pp
-Not all header semantics are defined in the configuration file.
-Header lines that should only be included by certain mailers
-(as well as other more obscure semantics)
-must be specified in the
-.i HdrInfo
-table in
-.i conf.c .
-This table contains the header name
-(which should be in all lower case)
-and a set of header control flags (described below),
-The flags are:
-.ip H_ACHECK
-Normally when the check is made to see if a header line is compatible
-with a mailer,
-.i sendmail
-will not delete an existing line.
-If this flag is set,
-.i sendmail
-will delete
-even existing header lines.
-That is,
-if this bit is set and the mailer does not have flag bits set
-that intersect with the required mailer flags
-in the header definition in
-sendmail.cf,
-the header line is
-.i always
-deleted.
-.ip H_EOH
-If this header field is set,
-treat it like a blank line,
-i.e.,
-it will signal the end of the header
-and the beginning of the message text.
-.ip H_FORCE
-Add this header entry
-even if one existed in the message before.
-If a header entry does not have this bit set,
-.i sendmail
-will not add another header line if a header line
-of this name already existed.
-This would normally be used to stamp the message
-by everyone who handled it.
-.ip H_TRACE
-If set,
-this is a timestamp
-(trace)
-field.
-If the number of trace fields in a message
-exceeds a preset amount
-the message is returned
-on the assumption that it has an aliasing loop.
-.ip H_RCPT
-If set,
-this field contains recipient addresses.
-This is used by the
-.b \-t
-flag to determine who to send to
-when it is collecting recipients from the message.
-.ip H_FROM
-This flag indicates that this field
-specifies a sender.
-The order of these fields in the
-.i HdrInfo
-table specifies
-.i sendmail 's
-preference
-for which field to return error messages to.
-.ip H_ERRORSTO
-Addresses in this header should receive error messages.
-.ip H_CTE
-This header is a Content-Transfer-Encoding header.
-.ip H_CTYPE
-This header is a Content-Type header.
-.ip H_STRIPVAL
-Strip the value from the header (for Bcc:).
-.nr ii 5n
-.lp
-Let's look at a sample
-.i HdrInfo
-specification:
-.(b
-.ta 4n +\w'"content-transfer-encoding",  'u
-struct hdrinfo	HdrInfo[] =
-\&{
-	     /* originator fields, most to least significant  */
-	"resent-sender",	H_FROM,
-	"resent-from",	H_FROM,
-	"sender",	H_FROM,
-	"from",	H_FROM,
-	"full-name",	H_ACHECK,
-	"errors-to",	H_FROM\^|\^H_ERRORSTO,
-	     /* destination fields */
-	"to",	H_RCPT,
-	"resent-to",	H_RCPT,
-	"cc",	H_RCPT,
-	"bcc",	H_RCPT\^|\^H_STRIPVAL,
-	     /* message identification and control */
-	"message",	H_EOH,
-	"text",	H_EOH,
-	     /* trace fields */
-	"received",	H_TRACE\^|\^H_FORCE,
-	     /* miscellaneous fields */
-	"content-transfer-encoding",	H_CTE,
-	"content-type",	H_CTYPE,
-
-	NULL,	0,
-};
-.)b
-This structure indicates that the
-.q To: ,
-.q Resent-To: ,
-and
-.q Cc:
-fields
-all specify recipient addresses.
-Any
-.q Full-Name:
-field will be deleted unless the required mailer flag
-(indicated in the configuration file)
-is specified.
-The
-.q Message:
-and
-.q Text:
-fields will terminate the header;
-these are used by random dissenters around the network world.
-The
-.q Received:
-field will always be added,
-and can be used to trace messages.
-.pp
-There are a number of important points here.
-First,
-header fields are not added automatically just because they are in the
-.i HdrInfo
-structure;
-they must be specified in the configuration file
-in order to be added to the message.
-Any header fields mentioned in the configuration file but not
-mentioned in the
-.i HdrInfo
-structure have default processing performed;
-that is,
-they are added unless they were in the message already.
-Second,
-the
-.i HdrInfo
-structure only specifies cliched processing;
-certain headers are processed specially by ad hoc code
-regardless of the status specified in
-.i HdrInfo .
-For example,
-the
-.q Sender:
-and
-.q From:
-fields are always scanned on ARPANET mail
-to determine the sender\**;
-.(f
-\**Actually, this is no longer true in SMTP;
-this information is contained in the envelope.
-The older ARPANET protocols did not completely distinguish
-envelope from header.
-.)f
-this is used to perform the
-.q "return to sender"
-function.
-The
-.q "From:"
-and
-.q "Full-Name:"
-fields are used to determine the full name of the sender
-if possible;
-this is stored in the macro
-.b $x
-and used in a number of ways.
-.sh 3 "Restricting Use of Email"
-.pp
-If it is necessary to restrict mail through a relay,
-the
-.i checkcompat
-routine can be modified.
-This routine is called for every recipient address.
-It returns an exit status
-indicating the status of the message.
-The status
-.sm EX_OK
-accepts the address,
-.sm EX_TEMPFAIL
-queues the message for a later try,
-and other values
-(commonly
-.sm EX_UNAVAILABLE )
-reject the message.
-It is up to
-.i checkcompat
-to print an error message
-(using
-.i usrerr )
-if the message is rejected.
-For example,
-.i checkcompat
-could read:
-.(b
-.re
-.sz -1
-.ta 4n +4n +4n +4n +4n +4n +4n
-int
-checkcompat(to, e)
-	register ADDRESS *to;
-	register ENVELOPE *e;
-\&{
-	register STAB *s;
-
-	s = stab("private", ST_MAILER, ST_FIND);
-	if (s != NULL && e\->e_from.q_mailer != LocalMailer &&
-	    to->q_mailer == s->s_mailer)
-	{
-		usrerr("No private net mail allowed through this machine");
-		return (EX_UNAVAILABLE);
-	}
-	if (MsgSize > 50000 && bitnset(M_LOCALMAILER, to\->q_mailer))
-	{
-		usrerr("Message too large for non-local delivery");
-		e\->e_flags |= EF_NORETURN;
-		return (EX_UNAVAILABLE);
-	}
-	return (EX_OK);
-}
-.sz
-.)b
-This would reject messages greater than 50000 bytes
-unless they were local.
-The
-.i EF_NORETURN
-flag can be set in
-.i e\(->e_flags
-to suppress the return of the actual body
-of the message in the error return.
-The actual use of this routine is highly dependent on the
-implementation,
-and use should be limited.
-.sh 3 "Load Average Computation"
-.pp
-The routine
-.i getla
-should return an approximation of the current system load average
-as an integer.
-There are several versions included on compilation flags
-as described above.
-.sh 3 "New Database Map Classes"
-.pp
-New key maps can be added by creating a class initialization function
-and a lookup function.
-These are then added to the routine
-.i setupmaps.
-.pp
-The initialization function is called as
-.(b
-\fIxxx\fP_map_init(MAP *map, char *args)
-.)b
-The
-.i map
-is an internal data structure.
-The
-.i args
-is a pointer to the portion of the configuration file line
-following the map class name;
-flags and filenames can be extracted from this line.
-The initialization function must return
-.sm TRUE
-if it successfully opened the map,
-.sm FALSE
-otherwise.
-.pp
-The lookup function is called as
-.(b
-\fIxxx\fP_map_lookup(MAP *map, char buf[], char **av, int *statp)
-.)b
-The
-.i map
-defines the map internally.
-The
-.i buf
-has the input key.
-This may be (and often is) used destructively.
-The
-.i av
-is a list of arguments passed in from the rewrite line.
-The lookup function should return a pointer to the new value.
-IF the map lookup fails,
-.i *statp
-should be set to an exit status code;
-in particular, it should be set to
-.sm EX_TEMPFAIL
-if recovery is to be attempted by the higher level code.
-.sh 3 "Queueing Function"
-.pp
-The routine
-.i shouldqueue
-is called to decide if a message should be queued
-or processed immediately.
-Typically this compares the message priority to the current load average.
-The default definition is:
-.(b
-bool
-shouldqueue(pri, ctime)
-	long pri;
-	time_t ctime;
-{
-	if (CurrentLA < QueueLA)
-		return (FALSE);
-	return (pri > (QueueFactor / (CurrentLA \- QueueLA + 1)));
-}
-.)b
-If the current load average
-(global variable
-.i CurrentLA ,
-which is set before this function is called)
-is less than the low threshold load average
-(option
-.b x ,
-variable
-.i QueueLA ),
-.i shouldqueue
-returns
-.sm FALSE
-immediately
-(that is, it should
-.i not
-queue).
-If the current load average exceeds the high threshold load average
-(option
-.b X ,
-variable
-.i RefuseLA ),
-.i shouldqueue
-returns
-.sm TRUE
-immediately.
-Otherwise, it computes the function based on the message priority,
-the queue factor
-(option
-.b q ,
-global variable
-.i QueueFactor ),
-and the current and threshold load averages.
-.pp
-An implementation wishing to take the actual age of the message into account
-can also use the
-.i ctime
-parameter,
-which is the time that the message was first submitted to
-.i sendmail .
-Note that the
-.i pri
-parameter is already weighted
-by the number of times the message has been tried
-(although this tends to lower the priority of the message with time);
-the expectation is that the
-.i ctime
-would be used as an
-.q "escape clause"
-to ensure that messages are eventually processed.
-.sh 3 "Refusing Incoming SMTP Connections"
-.pp
-The function
-.i refuseconnections
-returns
-.sm TRUE
-if incoming SMTP connections should be refused.
-The current implementation is based exclusively on the current load average
-and the refuse load average option
-(option
-.b X ,
-global variable
-.i RefuseLA ):
-.(b
-bool
-refuseconnections()
-{
-	return (CurrentLA >= RefuseLA);
-}
-.)b
-A more clever implementation
-could look at more system resources.
-.sh 3 "Load Average Computation"
-.pp
-The routine
-.i getla
-returns the current load average (as a rounded integer).
-The distribution includes several possible implementations.
-If you are porting to a new environment
-you may need to add some new tweaks.\**
-.(f
-\**If you do, please send updates to
-sendmail@Sendmail.ORG.
-.)f
-.sh 2 "Configuration in src/daemon.c"
-.pp
-The file
-.i src/daemon.c
-contains a number of routines that are dependent
-on the local networking environment.
-The version supplied assumes you have BSD style sockets.
-.pp
-In previous releases,
-we recommended that you modify the routine
-.i maphostname
-if you wanted to generalize
-.b $[
-\&...\&
-.b $]
-lookups.
-We now recommend that you create a new keyed map instead.
-.sh 1 "CHANGES IN VERSION 8"
-.pp
-The following summarizes changes
-since the last commonly available version of
-.i sendmail
-(5.67).
-For a detailed list,
-consult the file
-RELEASE_NOTES
-in the root directory of the
-.i sendmail
-distribution.
-.sh 2 "Connection Caching"
-.pp
-Instead of closing SMTP connections immediately,
-those connections are cached for possible future use.
-The advent of MX records made this effective for mailing lists;
-in addition,
-substantial performance improvements can be expected for queue processing.
-.sh 2 "MX Piggybacking"
-.pp
-If two hosts with different names in a single message
-happen to have the same set of MX hosts,
-they can be sent in the same transaction.
-Version 8 notices this and tries to batch the messages.
-.sh 2 "RFC 1123 Compliance"
-.pp
-A number of changes have been made to make
-.i sendmail
-.q "conditionally compliant"
-(that is,
-.i sendmail
-satisfies all of the
-.q MUST
-clauses and most but not all of the
-.q SHOULD
-clauses in RFC 1123).
-.pp
-The major areas of change are (numbers are RFC 1123 section numbers):
-.nr ii \w'5.3.1.1\0\0'u
-.ip 5.2.7
-Response to RCPT command is fast.
-.ip 5.2.8
-Numeric IP addresses are logged in Received: lines.
-.ip 5.2.17
-Self domain literal is properly handled.
-.ip 5.3.2
-Better control over individual timeouts.
-.ip 5.3.3
-Error messages are sent as
-.q From:<> .
-.ip 5.3.3
-Error messages are never sent to
-.q <> .
-.ip 5.3.3
-Route-addrs are pruned.
-.lp
-The areas in which
-.i sendmail
-is not
-.q "unconditionally compliant"
-are:
-.ip 5.2.6
-.i Sendmail
-does do header munging.
-.ip 5.2.10
-.i Sendmail
-doesn't always use the exact SMTP message text
-as listed in RFC 821.
-.ip 5.3.1.1
-.i Sendmail
-doesn't guarantee only one connect for each host in queue runs.
-.ip 5.3.1.1
-.i Sendmail
-doesn't always provide adequate concurrency limits.
-.sh 2 "Extended SMTP Support"
-.pp
-Version 8 includes both sending and receiving support for Extended
-SMTP support as defined by RFC 1651 (basic) and RFC 1653 (SIZE);
-and limited support for RFC 1652 (BODY).
-.sh 2 "Eight-Bit Clean"
-.pp
-Previous versions of
-.i sendmail
-used the 0200 bit for quoting.
-This version avoids that use.
-However, for compatibility with RFC 822,
-you can set option `7' to get seven bit stripping.
-.pp
-Individual mailers can still produce seven bit output using the
-`7' mailer flag.
-.sh 2 "User Database"
-.pp
-The user database is an as-yet experimental attempt
-to provide unified large-site name support.
-We are installing it at Berkeley;
-future versions may show significant modifications.
-.sh 2 "Improved BIND Support"
-.pp
-The BIND support,
-particularly for MX records,
-had a number of annoying
-.q features
-which have been removed in this release.
-In particular,
-these more tightly bind (pun intended) the name server to
-.i sendmail ,
-so that the name server resolution rules are incorporated directly into
-.b sendmail .
-.sh 2 "Keyed Files"
-.pp
-Generalized keyed files is an idea taken directly from
-.sm IDA
-.i sendmail
-(albeit with a completely different implementation).
-They can be useful on large sites.
-.pp
-Version 8 also understands YP.
-.sh 2 "Multi-Word Classes"
-.pp
-Classes can now be multiple words.
-For example,
-.(b
-CShofmann.CS.Berkeley.EDU
-.)b
-allows you to match the entire string
-.q hofmann.CS.Berkeley.EDU
-using the single construct
-.q $=S .
-.sh 2 "Deferred Macro Expansion"
-.pp
-The
-.b $& \c
-.i x
-construct has been adopted from
-.sm IDA .
-.sh 2 "IDENT Protocol Support"
-.pp
-The IDENT protocol as defined in RFC 1413 is supported.
-.sh 2 "Parsing Bug Fixes"
-.pp
-A number of small bugs having to do with things like
-backslash-escaped quotes inside of comments
-have been fixed.
-.sh 2 "Separate Envelope/Header Processing"
-.pp
-Since the From: line is passed in separately from the envelope sender,
-these have both been made visible;
-the
-.b $g
-macro is set to the envelope sender during processing
-of mailer argument vectors
-and the header sender during processing of headers.
-.pp
-It is also possible to specify separate per-mailer
-envelope and header processing.
-The
-.b S enderRWSet
-and
-.b R ecipientRWset
-arguments for mailers
-can be specified as
-.i envelope/header
-to give different rewritings for envelope versus header addresses.
-.sh 2 "Owner-List Propagates to Envelope"
-.pp
-When an alias has an associated owner\-list name,
-that alias is used to change the envelope sender address.
-This will cause downstream errors to be returned to that owner.
-.sh 2 "Dynamic Header Allocation"
-.pp
-The fixed size limit on header lines has been eliminated.
-.sh 2 "New Command Line Flags"
-.pp
-The
-.b \-B
-flag has been added to pass in body type information.
-.pp
-The
-.b \-p
-flag has been added
-to pass in protocol information.
-.pp
-The
-.b \-X
-flag has been added
-to allow logging of all protocol in and out of
-.i sendmail
-for debugging.
-.pp
-The
-.b \-O
-flag implies setting long-form options.
-.sh 2 "Enhanced Command Line Flags"
-.pp
-The
-.b \-q
-flag can limit limit a queue run to specific recipients, senders, or queue ids
-using
-.b \-qR\c
-.i substring ,
-.b \-qS\c
-.i substring ,
-or
-.b \-qI\c
-.i substring
-respectively.
-.sh 2 "New and Old Configuration Line Types"
-.pp
-The
-.b K
-line has been added to declare database maps.
-.pp
-The
-.b V
-line has been added to declare the configuration version level.
-.pp
-The
-.b M
-line has a
-.q D=
-field that lets you change into a temporary directory while that mailer
-is running.
-It also has a
-.q U=
-field to allow you to set the user and group id to be used
-when running the mailer.
-.sh 2 "New Options"
-.pp
-Several new options have been added,
-many to support new features,
-others to allow tuning that was previously available
-only by recompiling.
-They are described in detail in Section 5.6.
-Briefly,
-.nr ii 0.5i
-.ip b
-Insist on a minimum number of disk blocks.
-.ip C
-Set checkpoint interval.
-.ip E
-Default error message.
-.ip G
-Enable GECOS matching.
-.ip h
-Maximum hop count.
-.ip j
-Send errors in MIME-encapsulated format.
-.ip J
-Forward file path.
-.ip k
-Connection cache size
-.ip K
-Connection cache lifetime.
-.ip l
-Enable Errors-To: header.
-These headers violate RFC 1123;
-this option is included to provide back compatibility
-with old versions of
-.i sendmail .
-.ip O
-Set incoming SMTP daemon options, such as an alternate SMTP port.
-.ip p
-Privacy options.
-.ip R
-Don't prune route-addrs.
-.ip U
-User database spec.
-.ip V
-Fallback
-.q MX
-host.
-.ip w
-.q "Best MX"
-handling technique.
-.ip 7
-Do not run eight bit clean.
-.ip 8
-Eight bit data handling mode.
-.sh 2 "Extended Options"
-.pp
-The
-.b r
-(read timeout),
-.b I
-(use BIND),
-and
-.b T
-(queue timeout)
-options have been extended to pass in more information.
-.sh 2 "New Mailer Flags"
-.pp
-Several new mailer flags have been added.
-.ip a
-Try to use ESMTP when creating a connection.
-If this is not set,
-.i sendmail
-will still try if the other end hints that it knows about ESMTP
-in its greeting message;
-this flag says to try even if it doesn't hint.
-If the EHLO (extended hello)
-command fails,
-.i sendmail
-falls back to old SMTP.
-.ip A
-Try the user part of addresses for this mailer as aliases.
-.ip b
-Ensure that there is a blank line at the end of all messages.
-.ip c
-Strip all comments from addresses;
-this should only be used as a last resort
-when dealing with cranky mailers.
-.ip g
-Never use the null sender as the envelope sender,
-even when running SMTP.
-Although this violates RFC 1123,
-it may be necessary when you must deal with some obnoxious old hosts.
-.ip k
-Turn off the loopback check in the HELO protocol;
-doing this may cause mailer loops.
-.ip o
-Always run the mailer as the recipient of the message.
-.ip w
-This user should have a passwd file entry.
-.ip 5
-Try ruleset 5 if no local aliases.
-.ip 7
-Strip all output to 7 bits.
-.ip :
-Check for :include: files.
-.ip |
-Check for |program addresses.
-.ip /
-Check for /file addresses.
-.ip @
-Check this user against the user database.
-.sh 2 "Long Option Names"
-.pp
-All options can be specified using long names,
-and some new options can only be specified with long names.
-.sh 2 "New Pre-Defined Macros"
-.pp
-The following macros are pre-defined:
-.ip $k
-The UUCP node name,
-nominally from
-.i uname (2)
-call.
-.ip $m
-The domain part of our full hostname.
-.ip $_
-The RFC 1413-provided sender address.
-.sh 2 "New LHS Token"
-.pp
-Version 8 allows
-.b $@
-on the Left Hand Side of an
-.q R
-line to match zero tokens.
-This is intended to be used to match the null input.
-.sh 2 "Bigger Defaults"
-.pp
-Version 8 allows up to 100 rulesets instead of 30.
-It is recommended that rulesets 0\-9 be reserved for
-.i sendmail 's
-dedicated use in future releases.
-.pp
-The total number of MX records that can be used has been raised to 20.
-.pp
-The number of queued messages that can be handled at one time
-has been raised from 600 to 1000.
-.sh 2 "Different Default Tuning Parameters"
-.pp
-Version 8 has changed the default parameters
-for tuning queue costs
-to make the number of recipients more important
-than the size of the message (for small messages).
-This is reasonable if you are connected with reasonably fast links.
-.sh 2 "Auto-Quoting in Addresses"
-.pp
-Previously, the
-.q "Full Name <email address>"
-syntax would generate incorrect protocol output
-if
-.q "Full Name"
-had special characters such as dot.
-This version puts quotes around such names.
-.sh 2 "Symbolic Names On Error Mailer"
-.pp
-Several names have been built in to the $@ portion of the $#error
-mailer.
-.sh 2 "SMTP VRFY Doesn't Expand"
-.pp
-Previous versions of
-.i sendmail
-treated VRFY and EXPN the same.
-In this version,
-VRFY doesn't expand aliases or follow .forward files.
-EXPN still does.
-.pp
-As an optimization, if you run with your default delivery mode being
-queue-only or deliver-in-background,
-the RCPT command will also not chase aliases and .forward files.
-It will chase them when it processes the queue.
-.sh 2 "[IPC] Mailers Allow Multiple Hosts"
-.pp
-When an address resolves to a mailer that has
-.q [IPC]
-as its
-.q Path ,
-the $@ part (host name)
-can be a colon-separated list of hosts instead of a single hostname.
-This asks
-.i sendmail
-to search the list for the first entry that is available
-exactly as though it were an MX record.
-The intent is to route internal traffic through internal networks
-without publishing an MX record to the net.
-MX expansion is still done on the individual items.
-.sh 2 "Aliases Extended"
-.pp
-The implementation has been merged with maps.
-Among other things,
-this supports NIS-based aliases.
-.sh 2 "Portability and Security Enhancements"
-.pp
-A number of internal changes have been made to enhance portability.
-.pp
-Several fixes have been made to increase the paranoia factor.
-.sh 2 "Miscellaneous Changes"
-.pp
-.i Sendmail
-writes a
-.i /etc/sendmail.pid
-file with the current process id of the SMTP daemon.
-.pp
-Two people using the same program in their .forward file
-are considered different
-so that duplicate elimination doesn't delete one of them.
-.pp
-The
-.i mailstats
-program prints mailer names
-and gets the location of the
-.i sendmail.st
-file from
-.i /etc/sendmail.cf .
-.pp
-Many minor bugs have been fixed, such as handling of backslashes
-inside of quotes.
-.pp
-A hook (ruleset 5) has been added
-to allow rewriting of local addresses after aliasing.
-.sh 1 "ACKNOWLEDGEMENTS"
-.pp
-I've worked on
-.i sendmail
-for many years,
-and many employers have been remarkably patient
-about letting me work on a large project
-that was not part of my official job.
-This includes time on the INGRES Project at
-the University of California at Berkeley,
-at Britton Lee,
-and again on the Mammoth and Titan Projects at Berkeley.
-.pp
-Much of the second wave of improvements
-should be credited to Bryan Costales of ICSI.
-As he passed me drafts of his book on
-.i sendmail
-I was inspired to start working on things again.
-Bryan was also available to bounce ideas off of.
-.pp
-Many, many people contributed chunks of code and ideas to
-.i sendmail .
-It has proven to be a group network effort.
-Version 8 in particular was a group project.
-The following people made notable contributions:
-.(l
-John Beck, Hewlett-Packard
-Keith Bostic, CSRG, University of California, Berkeley
-Andrew Cheng, Sun Microsystems
-Michael J. Corrigan, University of California, San Diego
-Bryan Costales, International Computer Science Institute
-Pa\*:r (Pell) Emanuelsson
-Craig Everhart, Transarc Corporation
-Tom Ivar Helbekkmo, Norwegian School of Economics
-Allan E. Johannesen, WPI
-Jonathan Kamens, OpenVision Technologies, Inc.
-Takahiro Kanbe, Fuji Xerox Information Systems Co., Ltd.
-Brian Kantor, University of California, San Diego
-Murray S. Kucherawy, HookUp Communication Corp.
-Bruce Lilly, Sony U.S.
-Karl London
-Motonori Nakamura, Ritsumeikan University & Kyoto University
-John Gardiner Myers, Carnegie Mellon University
-Neil Rickert, Northern Illinois University
-Eric Schnoebelen, Convex Computer Corp.
-Eric Wassenaar, National Institute for Nuclear and High Energy Physics, Amsterdam
-Christophe Wolfhugel, Pasteur Institute & Herve Schauer Consultants (Paris)
-.)l
-I apologize for anyone I have omitted, misspelled, misattributed, or
-otherwise missed.
-At this point, I suspect that at least a hundred people
-have contributed code,
-and many more have contributed ideas, comments, and encouragement.
-I've tried to list them in the RELEASE_NOTES in the distribution directory.
-I appreciate their contribution as well.
-.pp
-Special thanks are reserved for Michael Corrigan and Christophe Wolfhugel,
-who besides being wonderful guinea pigs and contributors
-have also consented to be added to the ``sendmail@Sendmail.ORG'' list
-and, by answering the bulk of the questions sent to that list,
-have freed me up to do other work.
-.++ A
-.+c "COMMAND LINE FLAGS"
-.ba 0
-.nr ii 1i
-.pp
-Arguments must be presented with flags before addresses.
-The flags are:
-.ip \-b\fIx\fP
-Set operation mode to
-.i x .
-Operation modes are:
-.(b
-.ta 4n
-m	Deliver mail (default)
-s	Speak SMTP on input side
-a\(dg	``Arpanet'' mode (get envelope sender information from header)
-d	Run as a daemon in background
-D	Run as a daemon in foreground
-t	Run in test mode
-v	Just verify addresses, don't collect or deliver
-i	Initialize the alias database
-p	Print the mail queue
-.)b
-.(f
-\(dgDeprecated.
-.)f
-.ip \-B\fItype\fP
-Indicate body type.
-.ip \-C\fIfile\fP
-Use a different configuration file.
-.i Sendmail
-runs as the invoking user (rather than root)
-when this flag is specified.
-.ip \-d\fIlevel\fP
-Set debugging level.
-.ip "\-f\ \fIaddr\fP"
-The sender's machine address is
-.i addr .
-.ip \-F\fIname\fP
-Sets the full name of this user to
-.i name .
-.ip "\-h\ \fIcnt\fP"
-Sets the
-.q "hop count"
-to
-.i cnt .
-This represents the number of times this message has been processed
-by
-.i sendmail
-(to the extent that it is supported by the underlying networks).
-.i Cnt
-is incremented during processing,
-and if it reaches
-MAXHOP
-(currently 30)
-.i sendmail
-throws away the message with an error.
-.ip \-n
-Don't do aliasing or forwarding.
-.ip "\-N \fInotifications\fP"
-Tag all addresses being sent as wanting the indicated
-.i notifications ,
-which consists of the word
-.q NEVER
-or a comma-separated list of
-.q SUCCESS ,
-.q FAILURE ,
-and
-.q DELAY
-for successful delivery,
-failure,
-and a message that is stuck in a queue somewhere.
-The default is
-.q FAILURE,DELAY .
-.ip "\-r\ \fIaddr\fP"
-An obsolete form of
-.b \-f .
-.ip \-o\fIx\|value\fP
-Set option
-.i x
-to the specified
-.i value .
-These options are described in Section 5.6.
-.ip \-O\fIoption\fP\fB=\fP\fIvalue\fP
-Set
-.i option
-to the specified
-.i value
-(for long form option names).
-These options are described in Section 5.6.
-.ip \-M\fIx\|value
-Set macro
-.i x
-to the specified
-.i value .
-.ip \-p\fIprotocol\fP
-Set the sending protocol.
-Programs are encouraged to set this.
-The protocol field can be in the form
-.i protocol \c
-.b : \c
-.i host
-to set both the sending protocol and sending host.
-For example,
-.q \-pUUCP:uunet
-sets the sending protocol to UUCP
-and the sending host to uunet.
-(Some existing programs use \-oM to set the r and s macros;
-this is equivalent to using \-p.)
-.ip \-q\fItime\fP
-Try to process the queued up mail.
-If the time is given,
-a
-.i sendmail
-will run through the queue at the specified interval
-to deliver queued mail;
-otherwise, it only runs once.
-.ip \-q\fIXstring\fP
-Run the queue once,
-limiting the jobs to those matching
-.i Xstring .
-The key letter
-.i X
-can be
-.b I
-to limit based on queue identifier,
-.b R
-to limit based on recipient,
-or
-.b S
-to limit based on sender.
-A particular queued job is accepted if one of the corresponding addresses
-contains the indicated
-.i string .
-.ip "\-R ret"
-What information you want returned if the message bounces;
-.i ret
-can be
-.q HDRS
-for headers only or
-.q FULL
-for headers plus body.
-This is a request only;
-the other end is not required to honor the parameter.
-.ip \-t
-Read the header for
-.q To: ,
-.q Cc: ,
-and
-.q Bcc:
-lines, and send to everyone listed in those lists.
-The
-.q Bcc:
-line will be deleted before sending.
-Any addresses in the argument vector will be deleted
-from the send list.
-.ip "\-U"
-Indicate that this is an initial User Agent submission.
-In future releases, sendmail may complain about syntactically invalid messages
-rather than fixing them when this flag is not set.
-.ip "\-V envid"
-The indicated
-.i envid
-is passed with the envelope of the message
-and returned if the message bounces.
-.ip "\-X \fIlogfile\fP"
-Log all traffic in and out of
-.i sendmail
-in the indicated
-.i logfile
-for debugging mailer problems.
-This produces a lot of data very quickly and should be used sparingly.
-.pp
-There are a number of options that may be specified as
-primitive flags.
-These are the e, i, m, and v options.
-Also,
-the f option
-may be specified as the
-.b \-s
-flag.
-.+c "QUEUE FILE FORMATS"
-.pp
-This appendix describes the format of the queue files.
-These files live in the directory defined by the
-.b Q
-option in the
-.i sendmail.cf
-file, usually
-.i /var/spool/mqueue
-or
-.i /usr/spool/mqueue .
-.pp
-All queue files have the name
-\fIx\fP\|\fBf\fP\fIAAA99999\fP
-where
-.i AAA99999
-is the
-.i id
-for this message
-and the
-.i x
-is a type.
-The first letter of the id encodes the hour of the day
-that the message was received by the system
-(with A being the hour between midnight and 1:00AM).
-All files with the same id collectively define one message.
-.pp
-The types are:
-.nr ii 0.5i
-.ip d
-The data file.
-The message body (excluding the header) is kept in this file.
-.ip q
-The queue control file.
-This file contains the information necessary to process the job.
-.ip t
-A temporary file.
-These are an image of the
-.b qf
-file when it is being rebuilt.
-It should be renamed to a
-.b qf
-file very quickly.
-.ip x
-A transcript file,
-existing during the life of a session
-showing everything that happens
-during that session.
-.pp
-The
-.b qf
-file is structured as a series of lines
-each beginning with a code letter.
-The lines are as follows:
-.ip V
-The version number of the queue file format,
-used to allow new
-.i sendmail
-binaries to read queue files created by older versions.
-Defaults to version zero.
-Must be the first line of the file if present.
-.ip H
-A header definition.
-There may be any number of these lines.
-The order is important:
-they represent the order in the final message.
-These use the same syntax
-as header definitions in the configuration file.
-.ip C
-The controlling address.
-The syntax is
-.q localuser:aliasname .
-Recipient addresses following this line
-will be flagged so that deliveries will be run as the
-.i localuser
-(a user name from the /etc/passwd file);
-.i aliasname
-is the name of the alias that expanded to this address
-(used for printing messages).
-.ip Q
-The ``original recipient'',
-specified by the ORCPT= field in an ESMTP transaction.
-Used exclusively for Delivery Status Notifications.
-It applies only to the immediately following `R' line.
-.ip R
-A recipient address.
-This will normally be completely aliased,
-but is actually realiased when the job is processed.
-There will be one line
-for each recipient.
-Version 1 qf files
-also include a leading colon-terminated list of flags,
-which can be
-`S' to return a message on successful final delivery,
-`F' to return a message on failure,
-`D' to return a message if the message is delayed,
-`B' to indicate that the body should be returned,
-`N' to suppress returning the body,
-and
-`P' to declare this as a ``primary'' (command line or SMTP-session) address.
-.ip S
-The sender address.
-There may only be one of these lines.
-.ip T
-The job creation time.
-This is used to compute when to time out the job.
-.ip P
-The current message priority.
-This is used to order the queue.
-Higher numbers mean lower priorities.
-The priority changes
-as the message sits in the queue.
-The initial priority depends on the message class
-and the size of the message.
-.ip M
-A message.
-This line is printed by the
-.i mailq
-command,
-and is generally used to store status information.
-It can contain any text.
-.ip F
-Flag bits, represented as one letter per flag.
-Defined flag bits are
-.b r
-indicating that this is a response message
-and
-.b w
-indicating that a warning message has been sent
-announcing that the mail has been delayed.
-.ip N
-The total number of delivery attempts.
-.ip K
-The time (as seconds since January 1, 1970)
-of the last delivery attempt.
-.ip I
-The i-number of the data file;
-this can be used to recover your mail queue
-after a disastrous disk crash.
-.ip $
-A macro definition.
-The values of certain macros
-(as of this writing, only
-.b $r
-and
-.b $s )
-are passed through to the queue run phase.
-.ip B
-The body type.
-The remainder of the line is a text string defining the body type.
-If this field is missing,
-the body type is assumed to be
-.q "undefined"
-and no special processing is attempted.
-Legal values are
-.q 7BIT
-and
-.q 8BITMIME .
-.ip O
-The original MTS value (from the ESMTP transaction).
-For Deliver Status Notifications only.
-.ip Z
-The original envelope id (from the ESMTP transaction).
-For Deliver Status Notifications only.
-.pp
-As an example,
-the following is a queue file sent to
-.q eric@mammoth.Berkeley.EDU
-and
-.q bostic@okeeffe.CS.Berkeley.EDU \**:
-.(f
-\**This example is contrived and probably inaccurate for your environment.
-Glance over it to get an idea;
-nothing can replace looking at what your own system generates.
-.)f
-.(b
-P835771
-T404261372
-Seric
-Ceric:sendmail@vangogh.CS.Berkeley.EDU
-Reric@mammoth.Berkeley.EDU
-Rbostic@okeeffe.CS.Berkeley.EDU
-H?P?return-path: <owner-sendmail@vangogh.CS.Berkeley.EDU>
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-H?F?from: eric@foo.bar.baz.de (Eric Allman)
-H?x?full-name: Eric Allman
-Hmessage-id: <9207170931.AA22757@foo.bar.baz.de>
-HTo: sendmail@vangogh.CS.Berkeley.EDU
-Hsubject: this is an example message
-.)b
-This shows
-the person who sent the message,
-the submission time
-(in seconds since January 1, 1970),
-the message priority,
-the message class,
-the recipients,
-and the headers for the message.
-.+c "SUMMARY OF SUPPORT FILES"
-.pp
-This is a summary of the support files
-that
-.i sendmail
-creates or generates.
-Many of these can be changed by editing the sendmail.cf file;
-check there to find the actual pathnames.
-.nr ii 1i
-.ip "/usr/\*(SD/sendmail"
-The binary of
-.i sendmail .
-.ip /usr/\*(SB/newaliases
-A link to /usr/\*(SD/sendmail;
-causes the alias database to be rebuilt.
-Running this program is completely equivalent to giving
-.i sendmail
-the
-.b \-bi
-flag.
-.ip /usr/\*(SB/mailq
-Prints a listing of the mail queue.
-This program is equivalent to using the
-.b \-bp
-flag to
-.i sendmail .
-.ip /etc/sendmail.cf
-The configuration file,
-in textual form.
-.ip /usr/lib/sendmail.hf
-The SMTP help file.
-.ip /etc/sendmail.st
-A statistics file; need not be present.
-.ip /etc/sendmail.pid
-Created in daemon mode;
-it contains the process id of the current SMTP daemon.
-If you use this in scripts;
-use ``head \-1'' to get just the first line;
-later versions of
-.i sendmail
-may add information to subsequent lines.
-.ip /etc/aliases
-The textual version of the alias file.
-.ip /etc/aliases.{pag,dir}
-The alias file in
-.i dbm \|(3)
-format.
-.ip /var/spool/mqueue
-The directory in which the mail queue
-and temporary files reside.
-.ip /var/spool/mqueue/qf*
-Control (queue) files for messages.
-.ip /var/spool/mqueue/df*
-Data files.
-.ip /var/spool/mqueue/tf*
-Temporary versions of the qf files,
-used during queue file rebuild.
-.ip /var/spool/mqueue/xf*
-A transcript of the current session.
-.if e \
-\{\
-.	bp
-.	rs
-.	sp |4i
-.	ce 2
-This page intentionally left blank;
-replace it with a blank sheet for double-sided output.
-.\}
-.\".ro
-.\".ls 1
-.\".tp
-.\".sp 2i
-.\".in 0
-.\".ce 100
-.\".sz 24
-.\".b SENDMAIL
-.\".sz 14
-.\".sp
-.\"INSTALLATION AND OPERATION GUIDE
-.\".sp
-.\".sz 10
-.\"Eric Allman
-.\".sp
-.\"Version 8.106
-.\".ce 0
-.bp 3
-.ce
-.sz 12
-TABLE OF CONTENTS
-.sz 10
-.sp
-.\" remove some things to avoid "out of temp file space" problem
-.rm sh
-.rm (x
-.rm )x
-.rm ip
-.rm pp
-.rm lp
-.rm he
-.rm fo
-.rm eh
-.rm oh
-.rm ef
-.rm of
-.xp