Mail transfer agent


Mail transfer agent

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.

Overview

An MTA receives mail from another MTA (relaying) or from a mail user agent (MUA). The MTA works behind the scenes, while the user usually interacts with the MUA. Every time an MTA receives an e-mail, it will add a "Received:" trace header field to the top of the message. In this way, there is a record of which MTAs handled the e-mail and in which order. Upon final delivery, the "Return-Path:" header will also be added to record the return path.

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 sophisticated functionality.

According to one survey, sendmail, Microsoft Exchange Server, Postfix, and Exim together control over 85% of market share for SMTP service.Fact|date=September 2008

Another survey suggests a more balanced playing field, though it included hosted e-mail services such as Postini.MailChannels [http://www.oreillynet.com/pub/a/sysadmin/2007/01/05/fingerprinting-mail-servers.html Mail Server Survey] , 2006]

ee also

*MX record
*List of mail servers
*Comparison of mail servers
*Mail user agent
*Mail delivery agent

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Mail transfer agent — Pour les articles homonymes, voir MTA. Un Mail Transfer Agent est un logiciel pour serveur de transmission de courriers électroniques. Faute de traduction faisant référence, l abréviation MTA (prononcée en français) est utilisée par les… …   Wikipédia en Français

  • Mail Transfer Agent — Ein Mail Transfer Agent oder Message Transport Agent (MTA) ist die Software eines Mailservers, die E Mails entgegennimmt und sendet. MTAs kommunizieren sehr häufig nach dem Simple Mail Transfer Protocol, aber auch gemäß X.400. Der MTA des… …   Deutsch Wikipedia

  • Mail Transfer Agent — Pour les articles homonymes, voir MTA. Un Mail Transfer Agent est un logiciel pour serveur de transmission de courriers électroniques. Faute de traduction faisant référence, l abréviation MTA (prononcée en français) est utilisée par les… …   Wikipédia en Français

  • mail transfer agent — pašto siuntimo programa statusas T sritis informatika apibrėžtis Programa, skirta ↑elektroniniams laiškams gauti ir perduoti iš vieno tinklo kompiuterio į kitą, kol jie pasieks galinį persiuntimo punktą – laiškų gavėjų pašto serverį. Persiuntimui …   Enciklopedinis kompiuterijos žodynas

  • Mail transfer agent — MTA es una sigla en inglés que significa Mail Transport Agent (Agente de Transporte de Correos), y también Message Transport Agent (Agente de Transporte de Mensajes). En otras palabras, es el servidor de correo (SMTP) en sí y no la parte que usa… …   Enciclopedia Universal

  • Mail transfer agent — …   Википедия

  • Mail Transfer Agent — …   Википедия

  • Postfix (Mail Transfer Agent) — Postfix Basisdaten Aktuelle Version 2.8.5 (3. September 2011) Betriebssystem diverse Unix Derivate …   Deutsch Wikipedia

  • Mail delivery agent — Un Mail Delivery Agent (ou MDA) est le logiciel final du voyage d un courrier électronique. C est le MDA qui dépose le message dans la boîte aux lettres de l utilisateur. C est le MDA qui doit donc gérer des problèmes comme un disque plein ou… …   Wikipédia en Français

  • Mail delivery agent — (MDA, Агент доставки электронной почты)  программа, принимающая входящие электронные письма и доставляющая их на электронный ящик получателя (если адрес назначения расположен на том же компьютере) или перенаправляющая их на другой почтовый… …   Википедия


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