“Many of the popular Linux distributions today include Postfix
(written by Wietse Venema) as their choice for default mail
transport agent. I’ve come to really appreciate the benefits of
Postfix as a sendmail replacement. The advantages of Postfix
include enhanced security, relatively simple configuration, and
excellent performance.“Postfix’s increased security comes partly from its modular
design. Each process handles some portion of the mail delivery
cycle and none of these processes run setuid root. As has been
observed, Postfix doesn’t even trust itself…”