What exactly is IMAP4?
IMAP4 is the fourth revision of the Internet Message Access Protocol or as it was once known, the Interactive Mail Access Protocol. IMAP4 is a protocol which deals exclusively with the handling of email on the client side. It has absolutely nothing to do with the actual sending of email; that’s SMTP’s (Simple Mail Transfer Protocol) job. IMAP4 is after POP3’s (The Post Office Protocol, version 3) job and the authors realized that no one would want to switch from POP3, which is an extremely popular and well supported protocol, to IMAP4, which has still to prove itself out in the shark infested waters of the Internet, unless it offered some significant advantages over the latter. They also knew that they could not radically alter the model of the protocol without alienating every Internet programmer on the planet. So IMAP4 feels a lot like POP3 and offers a superset of the features that the latter supports, which means that IMAP4 supports more complex interaction between server and clien
