Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across Internet Protocol (IP) networks. SMTP was first defined by RFC 821 (1982, eventually declared STD 10), and last updated by RFC 5321 (2008) which includes the extended SMTP (ESMTP) additions, and is the protocol in widespread use today. SMTP uses TCP port 25. The protocol for new submissions (MSA) is effectively the same as SMTP, but it uses port 587 instead. SMTP connections secured by SSL are known by the shorthand SMTPS, though SMTPS is not a protocol in its own right.
While electronic mail servers and other mail transfer agents use SMTP to send and receive mail messages, user-level client mail applications typically only use SMTP for sending messages to a mail server for relaying. For receiving messages, client applications usually use either the Post Office Protocol (POP) or the Internet Message Access Protocol (IMAP) or a proprietary system (such as Microsoft Exchange or Lotus Notes/Domino) to access their mail box accounts on a mail server.
Read more about Simple Mail Transfer Protocol: History, Mail Processing Model, Protocol Overview, Outgoing Mail SMTP Server, SMTP Transport Example, Optional Extensions, Security and Spamming, Related Requests For Comments
Famous quotes containing the words simple, mail and/or transfer:
“‘Tis the gift to be simple ‘tis the gift to be free
‘Tis the gift to come down where you ought to be
And when we find ourselves in the place just right
‘Twill be in the valley of love and delight.”
—Unknown. ‘Tis the Gift to Be Simple.
AH. American Hymns Old and New, Vols. I–II. Vol. I, with music; Vol. II, notes on the hymns and biographies of the authors and composers. Albert Christ-Janer, Charles W. Hughes, and Carleton Sprague Smith, eds. (1980)
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—For the State of California, U.S. public relief program (1935-1943)
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—Edgar Allan Poe (1809–1849)