Mail retrieval agent
A mail retrieval agent 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. MRA is an automated agent that works on behalf of the user agent checks for the new incoming mail. 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.
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
The mail retrieval agent may support delivery of retrieved mail via the following mechanisms:- Via a mail transport agent
- 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