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:
“Christina Bailey: I was just thinking how much you can tell about a person from such simple things. Your car, for instance.
Mike Hammer: Now what kind of message does it send you?
Christina: You have only one real, lasting love.
Mike: Now who could that be?
Christina: You. You’re one of those self-indulgent males who thinks about nothing but his clothes, his car, himself. I’ll bet you do push-ups every morning just to keep your belly hard.”
—A.I. (Albert Isaac)
“The mail from Tunis, probably,
An easy Morning’s Ride—”
—Emily Dickinson (1830–1886)
“No sociologist ... should think himself too good, even in his old age, to make tens of thousands of quite trivial computations in his head and perhaps for months at a time. One cannot with impunity try to transfer this task entirely to mechanical assistants if one wishes to figure something, even though the final result is often small indeed.”
—Max Weber (1864–1920)