Binary package “postfix” in ubuntu intrepid
High-performance mail transport agent
Postfix is Wietse Venema's mail transport agent that started life as an
alternative to the widely-used Sendmail program. Postfix attempts to
be fast, easy to administer, and secure, while at the same time being
sendmail compatible enough to not upset existing users. Thus, the outside
has a sendmail-ish flavor, but the inside is completely different.