Sendmail

Sendmail is an open source mail transfer agent (MTA): a computer program for the routing and delivery of email. Its authors released the current version, sendmail 8.13.0, on June 20, 2004. (Note the numbering style used: version 8.13.0 has obsoleted both 8.12.9 and 8.9 and their security vulnerabilities, despite their appearing "higher" in ordinary decimal numeration.) A descendant of the original ARPANET delivermail application, sendmail is a remarkably flexible program, supporting many kinds of mail transfer and delivery including the overwhelmingly popular SMTP. The original version of Sendmail was written by Eric Allman in the early 1980s at UC Berkeley, who had also written delivermail previously. Delivermail was shipped in 1979 with 4.0 and 4.1 BSD. Sendmail was shipped with BSD 4.1c in 1983 (the first BSD version to include TCP/IP). Sendmail has been widely criticized as slow, overcomplicated, and difficult to maintain by comparison with other MTAs such as Exim, Qmail and Postfix. Nevertheless it remains the most popular MTA on the Internet, a fact almost certainly due in part to its position as the standard MTA under most variants of the Unix operating system. According to one study, as of November 2001 approximately 42% of the publicly reachable mail servers on the Internet were running sendmail on some form of Unix system. Sendmail is often run as the root user, representing a severe security threat if compromised. This is despite the recommendation since 2001 by its authors that it be run as an unprivileged user.

References

• Sendmail Consortium, sendmail.org\n* Sendmail, Inc., sendmail.com\n* Daniel J. Bernstein, Internet host SMTP server survey, November 2001\n* Mike Brodbelt, A brief history of mail\n* Sendmail Configuration howto, Sendmail Configuration and Building a sendmail.cf file\n* Marco D'itri, Sendmail considered harmful (Italian; babelfish)

\n\nCategory:Free software\nCategory:Mail transport agents