Sendmail Inc.: Commercial support for sendmail. Last modification on December 20 2000.
Exim: Exim is a message transfer agent (MTA) developed at the University of
Cambridge for use on Unix systems connected to the Internet. It is freely
available under the terms of the GNU General Public Licence. In style it is
similar to Smail 3, but its facilities are more extensive, and in particular it
has some defences against mail bombs and unsolicited junk mail in the form of
options for refusing messages from particular hosts, networks, or senders. Last modification on November 27 2000.
Postfix: Postfix is an attempt to provide an alternative to the widely-used
Sendmail program. Postfix attempts to be fast, easy to administer, and
hopefully secure, while at the same time being sendmail compatible enough to
not upset your users. Last modification on December 15 2000.
Listar: Modular Mailing list management software Last modification on October 18 2000.