Mail retrieval agent

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A mail retrieval agent (MRA) is a computer application that retrieves or fetches e-mail from a remote mail server and works with a mail delivery agent to deliver mail to a local or remote email mailbox.[citation needed] MRAs may be external applications by themselves or be built into bigger applications like a mail user agent. Significant examples of standalone MRAs include fetchmail and getmail.[1][user-generated source]

The concept of an MRA is not standardized in email architecture. Although they operate like mail transfer agents, MRAs are technically clients when they retrieve and submit messages.

Delivery mechanisms[edit]

The mail retrieval agent may support delivery of retrieved mail via the following mechanisms:

  • Via a mail transport agent (Listening for SMTP transfers on port 25)
  • Via a mail delivery agent
  • Direct delivery to an mbox formatted mailbox
  • Direct delivery to a maildir directory
  • Output to standard output

Multiple mailbox support[edit]

The mail retriever agent may support retrieval of mail from multiple mailboxes simultaneously. This enables a mailserver to have a centrally configured mail retriever agent that runs against a dedicated mail system account, and collects the mail for all users in a single invocation (rather than using cron to run a mail retriever agent against all the mail recipients).

See also[edit]



  • Faircloth, Jeremy (25 Nov 2013). Enterprise Applications Administration: The Definitive Guide to Implementation and Operations. Newnes. ISBN 9780124078871.
  • EC-Council (20 Dec 2012). Network Defense: Security and Vulnerability Assessment. Cengage Learning. ISBN 978-1435483590.
  • Vakali, Athena (30 Sep 2006). Web Data Management Practices: Emerging Techniques and Technologies. Idea Group Inc (IGI). ISBN 9781599042305.
  • McBee, Jim (26 Jan 2009). Mastering Microsoft Exchange Server 2007 SP1. John Wiley & Sons. ISBN 9780470478141.