Free and open source mail transfer agent (MTA) that routes and delivers email. When asking about postfix problem, please include the relevant maillog lines and output of the following command: "postconf -n" (content of main.cf) and/or "postconf -M" (content of master.cf)
Postfix was written by Wietse Venema in 1997 and first released in December 1998 as IBM Secure Mailer.
It was designed to be highly secure and configurable, and is a drop-in replacement for sendmail, with much simpler configuration syntax.
The software was also formerly known as VMailer.