“Eric Allman’s sendmail moves the bulk of email through the
Internet. As the premier mail transport agent (MTA) using SMTP
(Simple Mail Transfer Protocol), sendmail can be found in every
major Linux distribution. However, sendmail is not without its
competitors, and perhaps the most prominent one is qmail, developed
by Dan Bernstein. While there are many alternative MTAs for Linux,
we take a look at sendmail and qmail to see why you might choose
one over the other. Both are available as Open Source software
at no cost, making the initial price a non-issue, but other costs
discussed later may come into play.”
“In general, sendmail has some significant advantages. It is
very mature being on the of oldest MTAs around. Its wide use and
availability has given rise to a vast number of experienced
sendmail administrators and consultants. It is also one of the
better documented applications, with books like O’Reilly’s sendmail
book written by Bryan Costales with Eric Allman. There are also
extensive online tutorials, FAQ files and other resources. This
documentation is important because of the vast array of features in
sendmail.”
“Of course, sendmail has some disadvantages. Its feature list is
only rivaled by the complexity of the sendmail configuration file.
The use of the m4 macro processor makes generation of the
sendmail.cf configuration file significantly easier, but
understanding all sendmail’s options can be a daunting task.
Sendmail has also has some security problems in the past making it
imperative that the latest updates are applied.”