Internet Message Access Protocol, version 4 (IMAP4)
(I) An Internet protocol (RFC 2060) by which a client workstation
can dynamically access a mailbox on a server host to manipulate
and retrieve mail messages that the server has received and is
holding for the client. (See: POP3.)
Tutorial: IMAP4 has mechanisms for optionally authenticating a
client to a server and providing other security services. (See:
IMAP4 AUTHENTICATE.)