Internet Message Access Protocol

What Does Internet Message Access Protocol Mean?

Internet Message Access Protocol (IMAP) is a standard protocol for accessing email on a remote server from a local client. IMAP is an application layer Internet Protocol using the underlying transport layer protocols to establish host-to-host communication services for applications. This allows the use of a remote mail server. The well-known port address for IMAP is 143.


The IMAP architecture enables users to send and receive emails through a remote server, without support from a particular device. This type of email access is ideal for travelers receiving or answering emails from their home desktop or office computer.

This term is also known as interactive mail access protocol, Internet mail access protocol, and interim mail access protocol

Techopedia Explains Internet Message Access Protocol

IMAP was originally designed as a remote mailbox protocol in 1986 by Mark Crispin. This was during the popular use of Post Office Protocol (POP). IMAP and POP are still both supported by the majority of modern email servers and clients. However, IMAP is a remote file server, while POP istores and forwards. In other words, with IMAP, all emails remain on the server until the client deletes them. IMAP also permits multiple clients to access and control the same mailbox.

When a user requests an email, it is routed through a central server. This keeps a storage document for the email files. Some of IMAP benefits include the ability to delete messages, search for keywords in the body of emails, create and manage multiple mailboxes or folders, and view the headings for easy visual scans of emails.

IMAP is still used extensively, but is less important now that so much email is sent via web-based interfaces such as gMail, Hotmail, Yahoo Mail, etc.


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Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…