Computing Dictionary
Message Transfer Agent definition
messaging (MTA, Mail Transfer Agent) Any program responsible for delivering
e-mail messages. Upon receiving a message from a
Mail User Agent or another MTA, often by
SMTP over the
Internet, it stores it temporarily locally and analyses the recipients and delivers it to any local addressees and/or forwards it to other remote MTAs (
routing) for delivery to remote recipients. In either case it may edit and/or add to the message
headers.
The most widely used MTA for
Unix is
sendmail, which communicates using
SMTP.
[Other OSes?]
RFC 2821 (SMTP) expands MTA as "Mail Transfer Agent" though this is less common. Alternatives with "Transport" are also seen but less correct.
(2007-06-01)