"Postfix, designed by Wietse Venema, is a mail server built with
security in mind and specifically designed to replace Sendmail. The
project began development in a security sensitive atmosphere. This
secure focus has had a major advantage over a product like Sendmail
that was created in a non-hostile environment and then had to be
adapted to protect users form the evils of the common day. Postfix
simplicity and focus on security are both major reasons why it is
selected over Sendmail. This tutorial will show you how to
configure a basic Postfix Mail server for CentOS,OpenSuse and
Ubuntu..."