Mail server

From CNM Wiki
Revision as of 14:36, 19 June 2019 by Gary (talk | contribs)
Jump to: navigation, search

A mail server (hereinafter, the Server) is any software instance that transfers electronic mail messages from or to other Servers using the Simple Mail Transfer Protocol (SMTP). The Servers may also take the messages from sender's mail user agents (MUAs) and deliver those to recipient's MUAs, usually, using POP3 and/or IMAP protocols.

The Server can also refer to mail server software. More broadly, email software refers to all the software utilized for both the Server and MUAs.


Categories

The Server may be one of the following four:

  1. Mail submission agent (also known as outgoing mail server, message submission agent or by its acronym MSA);
  2. Mail transfer agent (also known as message transfer agent or by its acronym MTA);
  3. Mail exchanger (also known as mail relay, message exchanger or MX, and MX host);
  4. Mail delivery agent (also known as incoming mail server, message delivery agent or by its acronym MDA).

Common senders submit their electronic mail messages to their MUA, which transfers the message to the mail submission agent, which transfers the message to either mail delivery agent or mail exchanger between the two. Finally, the mail delivery agent transfers the message to receiver's MUA.

Best practices