Best SMTP Services for MailRoute

What is Postfix? It is Wietse Venema’s mail server. It was originally developed by IBM Research as an alternative to Sendmail. Wietse Venema continues to support Postfix at Google. Postfix works (or has worked) on AIX and BSD, HPUX, IRIX. LINUX. MacOS X. Solaris. Tru64 UNIX. It requires ANSI C and a POSIX.1 librarian. Postfix aims to be fast, simple to administer, and secure. Although the outside is very Sendmail-ish, the inside is entirely different. Multiple SMTP delivery over the same TLS encrypted connection. This reuses existing tlsproxy(8), scache(8) services. MySQL stored procedure support. Gradual degradation: In many cases, a Postfix daemon will log an error and continue to provide services that are still available instead of terminating with a fatality. Postfix can set an execute bit in a queue file. If this fails, no mail will be delivered.

Exim is a mail-transfer agent (MTA), which can be used in Unixllike operating system. Philip Hazel wrote the first version in 1995 for the University of Cambridge Computing Service's email systems. Exim is available under the GPL and is free to download and modify. Exim is somewhat similar to Smail 3. However, it has diverged from it and now exceeds it in ease-of-use and flexibility. Both follow the Sendmail design model, where one main binary controls all facilities of the MTA. Some consider this monolithic design to be less secure and slower. However, Exim's security record and speed are better than Sendmail. It excels in advanced areas like address routing, queue handling, and testing. Exim does not have a Graphical User Interface (GUI), but some Linux distributions do.