maildrop is a replacement for your local mail delivery agent,
similar to mail/procmail.
- maildrop reads a mail message from standard input, 
  then delivers the message to your mailbox. 
- maildrop will optionally read instructions from a file, 
  which describes how to filter incoming mail. 
  Instructions can be provided having mail delivered to 
  alternate mailboxes, or forwarded somewhere else. 
  Unlike procmail, maildrop uses a structured filtering language.
- maildrop knows how to deliver mail to mbox-style mailboxes and maildirs.
- maildrop is written in C++, and handles resources more efficiently.

maildrop can be used with sendmail, qmail, and other MTAs.

WWW:	http://www.flounder.net/~mrsam/maildrop/