Internet Message Access Protocol | RFC1730

IMAP is a protocol for retrieving e-mail messages.

The latest version IMAP4 is similar to POP3 but supports some additional
features. For example IMAP4 can search through your mail messages for keywords
while the messages are still on the mail server. You can then choose which messages
to download to your machine and which messages you do not want to be downloaded.

IMAP was developed at Stanford University in 1986.

See also : POP3, SMTP