Simple Mail Transfer Protocol

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Simple Mail Transfer Protocol

[¦sim·pəl ′māl ‚tranz·fər ‚prōd·ə‚kȯl]
(computer science)
An Internet standard for sending e-mail messages. Abbreviated SMTP.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Simple Mail Transfer Protocol

(SMTP) A protocol defined in STD 10, RFC 821, used to transfer electronic mail between computers, usually over Ethernet. It is a server to server protocol, so other protocols are used to access the messages. The SMTP dialog usually happens in the background under the control of the message transfer agent, e.g. sendmail but it is possible to interact with an SMTP server using telnet to connect to the normal SMTP port, 25. E.g.

telnet 25

You should normally start by identifying the local host:


You can then issue commands to verify an address or expand an alias:

VRFY VRFY postmaster

or expand a mailing list:

EXPN c-help

You can even send a message:

MAIL From:<> RCPT To:<> DATA What is the point? . QUIT

This is useful if you want to find out exactly what is happening to your message at a certain point.

See also Post Office Protocol, RFC 822, sendmail.
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(Simple Mail Transfer Protocol) The standard email protocol on the Internet and part of the TCP/IP protocol suite, as defined by IETF RFC 2821. SMTP defines the message format and the message transfer agent (MTA), which stores and forwards the mail. SMTP was originally designed for only plain text (ASCII text), but MIME and other encoding methods enable executable programs and multimedia files to be attached to and transported with the email message.

SMTP servers route SMTP messages throughout the Internet to a mail server that provides a message store for incoming mail. The mail server uses the POP3 or IMAP4 access protocol to communicate with the user's email program. See POP3, IMAP4, MIME and messaging system. See also SNMP.
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References in periodicals archive ?
While designed primarily for Internet transmissions, it also can be used on TCP/IP networks that rely on the Simple Mail Transfer Protocol.
The Internet uses something called the simple mail transfer protocol, or SMTP for short, to deliver mail.
Or rather, that no one noticed sooner how nicely the basic structure of the Simple Mail Transfer Protocol (SMTP) and the Domain Name Service (DNS) could mesh to provide a killer added-value play in the email space.
Sure, mail actually has its own protocol to run over the Internet, SMTP (Simple Mail Transfer Protocol), and you don't need the Web to send or receive mail.
SIP (Session Initiation Protocol), is part of the IETF (Internet Engineering Task Force) standards process and is modeled upon other Internet protocols such as SMTP (Simple Mail Transfer Protocol) and HTTP (Hypertext Transfer Protocol).
During the early days of the Internet, the traffic composition was dominated by protocols such as simple mail transfer protocol (SMTP)and file transfer protocol (FTP).
The interface complements Banyan's plans for SMTP (Simple Mail Transfer Protocol) integration by meeting the needs of organizations where a single directory service is an important requirements.
The server can also send and receive documents to and from internal and external recipients by using the T.37 international protocol standard to deliver the fax communication embedded in an e-mail message over SMTP (simple mail transfer protocol) mail.
While the Internet has standardized on the TCP/IP protocols the Domain Name System (DNS), and the Simple Mail Transfer Protocol (SMTP), and developed highspeed links, BITNET development has lagged behind.
Conformance testing included A Series TCP/IP product performance in the various Application Layer services, including File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP), and the remote login service provided by TELNET.
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Given this diverse set of trading partners, selection of a robust extended simple mail transfer protocol (SMTP)-with-POP3 mailbox service is appropriate.