Internet mail access protocol (IMAP)

The Internet Mail Access Protocol (IMAP) was developed in 1988 and is used for connectionless access from Mail User Agents( MUA) to Mail Transfer Agents( MTA) in order to manage, open or pick up e-mails there.

This efficient e-mail protocol replaces the Post Office Protocol( POP) and allows messages to be transferred only as needed. For this purpose, only the headers are transmitted first and, after selection, the attachments. Using IMAP, hierarchical mailboxes can be set up and managed on the mail server from the workstation computer. This includes searching, deleting, copying, saving and downloading messages as well as changing the message status.

IMAP has the advantage that message storage works independently of the client software used. It is predestined for use in companies because it can also be used in groupware environments. An interesting feature is the possibility to select the e-mails in the mail server. This eliminates the need for copying and subsequent selection, which saves costs, especially for mobile communication via laptops and handhelds.

IMAP is supported by all major mail servers. Since IMAP is already in its fourth version, the current designation is IMAP4.