A mail retrieval agent (MRA) is a
computer application
Application may refer to:
Mathematics and computing
* Application software, computer software designed to help the user to perform specific tasks
** Application layer, an abstraction layer that specifies protocols and interface methods used in a c ...
that retrieves or fetches
e-mail
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...
from a remote mail server and works with a
mail delivery agent A message delivery agent (MDA), or mail delivery agent, is a computer software component that is responsible for the delivery of e-mail messages to a local recipient's mailbox., ''Internet Mail Architecture'', D. Crocker (July 2009) It is also calle ...
to deliver mail to a local or remote
email mailbox. MRAs may be external applications by themselves or be built into bigger applications like a
mail user agent
The mail or post is a system for physically transporting postcards, letters, and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal syst ...
. Significant examples of standalone MRAs include
fetchmail and
getmail.
MuttWiki: MailConcept
/ref>
The concept of an MRA is not standardized in email architecture. Although they operate like mail transfer agent
The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...
s, MRAs are technically clients when they retrieve and submit messages.
Delivery mechanisms
The mail retrieval agent may support delivery of retrieved mail via the following mechanisms:
* Via a mail transport agent (Listening for SMTP
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typic ...
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
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
* Email agent (infrastructure)
An e-mail agent is a program that is part of the e-mail infrastructure, from composition by sender, to transfer across the network, to viewing by recipient. The best-known are message user agents (MUAs, aka, e-mail clients) and message transfer a ...
(MxA)
References
Bibliography
*
*
*
*
Email agents
{{network-software-stub