message transfer agent

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Message Transfer Agent

(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.

RFC 2821 (SMTP) expands MTA as "Mail Transfer Agent" though this is less common. Alternatives with "Transport" are also seen but less correct.
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message transfer agent

The store and forward capability in a messaging system. See messaging system.
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References in periodicals archive ?
IMA will also release a free scaled-down option for small office/home office customers - a message transfer agent packaged with a three-user licence in its message store but with several key features disabled.
The MD Store messaging server based on IMAP4 and SASL and the MD Switch, a high-volume message transfer agent supporting both Internet Mail (SMTP/MIME) and X.400, are also available on IRIX.
Messenger 400 has APIs at each layer of the X.400 implementation to enable integration of user interfaces, gateways, applications access to the message transfer agent (MTA) and network layers.

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