Also found in: Wikipedia.


The BSD Unix Message Transfer Agent supporting mail transport via TCP/IP using SMTP. Sendmail is normally invoked in the background via a Mail User Agent such as the mail command.

Sendmail was written by Eric Allman at the University of California at Berkeley during the late 1970s. He now has his own company, Sendmail Inc.

Sendmail was one of the first programs to route messages between networks and today is still the dominant e-mail transfer software. It thrived despite the awkward ARPAnet transition between NCP to TCP protocols in the early 1980s and the adoption of the new SMTP Simple Mail Transport Protocol, all of which made the business of mail routing a complex challenge of backward and forward compatibility for several years. There are now over one million copies of Sendmail installed, representing over 75% of all Internet mail servers.

Simultaneously with the announcement of the company in November 1997, Sendmail 8.9 was launched, featuring new tools designed to limit junk e-mail. SendMail 8.9 is still distributed as source code with the rights to modify and distribute.

Latest version: 8.9.1, as of 1998-08-25.

The command

sendmail -bv ADDRESS

can be used to learn what the local mail system thinks of ADDRESS. You can also talk to the Sendmail daemon on a remote host FOO with the command

telnet FOO 25


An SMTP-based message transfer agent (MTA) that runs under Unix. Developed at the University of California at Berkeley by Eric Allman in 1981, sendmail stores and forwards more mail than any other MTA on the Internet. In 1998, Allman commercialized the product by forming Sendmail, Inc. (, which offers a GUI interface for modifying the configuration file instead of dealing directly with more than a thousand lines of text. Sendmail, Inc. also offers a Windows version that includes the POP mail server and message store. Examples of mail clients developed for sendmail in the Unix world are elm, pine, mush and mailx. For information on the open source version, visit See messaging system, BSD Unix and qmail.

Enterprise Mail System
This is a typical architecture of a large enterprise mail system. (Illustration assistance courtesy of Sendmail, Inc.)
References in periodicals archive ?
14, 2013 /PRNewswire/ -- Sendmail today introduced Sentrion Rogue Email Application Control (REAC) 2.
Cloudmark Inc, one of the tsunami of anti-spam software startups to hit the market the last couple of years, has gone some way to ensuring its continued existence by inking an exclusive OEM deal with Sendmail Inc, which makes the popular email software.
Sendmail, an e-mail security company, has launched its Sendmail Advanced Anti-Spam Filter for companies wishing to cut down on the amount of unwanted e-mails they receive.
By exploiting the power of Linux on the IBM mainframe platform, Sendmail provides the robustness and scalability needed for today's messaging and mail infrastructure with the industry's lowest total cost of computing.
Numerous Sendmail customers presented on various topics ranging from the challenges of moving email to the cloud, best practices on conducting a messaging architecture review before embarking on an email infrastructure modernization project, virtualizing an email backbone to how companies can use applications from the Sentrion Application Store to add further value to their Sentrion-based email infrastructure.
We've detected serious security and compliance risks posed by the growing volume of email messages being generated by all kinds of rogue systems and applications under IT's radar," said Sendmail Vice President of Marketing Barry Shurtz in advance of the conference.
Sendmail Inc has signed an OEM agreement with MessagingDirect Ltd of Edmonton, Canada, a maker of message store and access technologies.
the leading provider of message processing appliances and applications for enterprise messaging infrastructures, today announced from the Sendmail International Messaging Infrastructure Summit in Las Vegas, Nevada, that it has partnered with Totemo AG to provide Sentrion customers further message encryption options on the Sentrion Application Store.
Internet mail server startup Sendmail Inc plans significant expansion into Asian markets.
the leading provider of message processing appliances and applications for enterprise messaging infrastructures, today announced that their flagship Sendmail Sentrion product linehas been placed on the Modules-In Process List for the Federal Information Processing Standards Publications (FIPS) 140-2 Validation: Security Requirements for Cryptographic Modules.
A set of tools and consultative services delivered by Sendmail Messaging Architects to help organizations evaluate current messaging infrastructure, assess needs, and plan for their migration of email to the cloud.
Sendmail Inc has now announced that Sendmail Pro, the first enhanced commercial version of the well-known open source software sendmail will become generally available on January 25th.