sSMTP is an extremely simple MTA (Mail Transport Agent) to get mail off the system to a mail hub. It is a sendmail replacement.
This sSMTP program replaces sendmail on workstations that should send their mail via the departmental mailhub from which they pick up their mail (via pop, imap, rsmtp, pop_fetch, NFS... or the like). This program accepts mail and sends it to the mailhub, optionally replacing the domain in the From: line with a different one.
WARNING: the above is all it does. It does not receive mail, expand aliases or manage a queue. That belongs on a mailhub with a system administrator. The man page (ssmtp.8) and the program logic manual (ssmtp_plm) discuss the limitations in more detail.
It uses a minimum of external configuration information, and so can be installed by copying the (right!) binary and an optional four-line config file to a given machine.
Type of systems supported:
Berkeley-derived, or ones otherwise using /usr/lib/sendmail as a mail transfer agent. In use on SunOS 4.1.1, NextStep 2.x/3 and Ultrix 4.2, tested briefly on AIX 3.2 and RISCos. Tested by others on DG U/X 5 and SVR4.
You may need to #define USE_OLD_ARPADATE for the Cygwin port of ssmtp (otherwise the day of the month would always be the letter "d").