Mail transfer agent
From Wikipedia, the free encyclopedia
A mail transfer agent (MTA) (also called a mail transport agent, message transfer agent, or smtpd (short for SMTP daemon)), is a computer program or software agent that transfers electronic mail messages from one computer to another.
The term mail server is also used to mean a computer acting as an MTA that is running the appropriate software. The term mail exchanger (MX), in the context of the Domain Name System formally refers to an IP address assigned to a device hosting a mail server, and by extension also indicates the server itself.
[edit] Overview
An MTA receives mail from another MTA (relaying), from a mail user agent (MUA), thus acting as a mail submission agent (MSA), or from a MSA from that got the mail from a MUA. The MTA works behind the scenes, while the user usually interacts with the MUA.
The delivery of e-mail to a user's mailbox typically takes place via a mail delivery agent (MDA); many MTAs have basic MDA functionality built in, but a dedicated MDA like procmail can provide more sophistication.
According to various surveys [1] [2] [3] [4] the most popular mail server software are sendmail, Postfix, Microsoft Exchange Server, Exim, IMail (by Ipswitch, Inc.), MDaemon by Alt-N Technologies, MailEnable, Merak Mail Server and qmail. [5] The MailChannels survey[2] also found that many organizations use the services of e-mail security services such as Postini, MXLogic or Concentric Hosting to receive e-mail.
[edit] See also
[edit] Mail server surveys
- ^ Security Space Mail (MX) Server Survey, 1st Aug 2007.
- ^ a b MailChannels Mail Server Survey, 2006
- ^ Anonymous, Open source Mail Server Comparison, November 2003
- ^ Daniel J. Bernstein, Internet host SMTP server survey, November 2001
- ^ Dan Shearer, MTA Comparison, January 2007
es:Mail transfer agent fr:Serveur de messagerie électronique id:Mail transfer agent it:Mail server li:Mail transfer agent nl:Mailserver ja:メール転送エージェント pl:MTA pt:MTA ru:Почтовый сервер sr:MTA th:เมลเซิร์ฟเวอร์
