The stunnel program is designed to work  as  SSL  encryption
wrapper between remote client and local (inetd-startable) or
remote server. The concept is that having non-SSL aware dae-
mons  running  on  your  system you can easily setup them to
communicate with clients over secure SSL channel.

stunnel can be used to add  SSL  functionality  to  commonly
used  inetd  daemons  like  POP-2,  POP-3  and  IMAP servers
without any changes in the programs' code.

WWW: https://www.stunnel.org/