sendmail, 4th Edition

Other MTAs

The sendmail program is not the only MTA on the block. Others have existed for some time, and new MTAs appear on the scene every once in a while. Here we describe a few of the other major MTAs:

qmail

Stressing modularity and security, qmail claims to be a replacement for sendmail. The qmail program is an open source offering, available from http://www.qmail.org.

Postfix

Written by Wietse Venema, a security expert on the IBM Research staff, Postfix is advertised to be a drop-in replacement for sendmail that purports to deliver email more quickly, conveniently, and safely. The Postfix program is an open source offering, available from http://www.postfix.com.

Sun ONE Messaging Server

This MTA is a multithreaded commercial product that purports to be faster and more scalable than sendmail, and is part of a large commercial offering. Information can be found at http://www.sun.com.

Sendmail Switch^[4]

This is the same sendmail we describe here, but with selected commercial enhancements, and a suite of support software that forms a complete email solution. Additional information can be found at http://www.sendmail.com.

Many other MTAs exist, some good and some not so good. We mention only five here because, after all, this is a book about the open source sendmail.

^{[4] *} This is a professional MTA product, so like sendmail itself, it is, in a sense, a crossbar “switch.”