Internet Message Access Protocol.
An IETF standard (RFC 2193) protocol for accessing e-mail. IMAP enables the client to manage mail much more effectively than POP3, an earlier standard that is widely deployed. IMAP enables the user to view the header of each mail message before deciding whether to download it, delete it, or take other action. IMAP also enables the user to create, manipulate, and delete individual mail folders and mailboxes on the server. However, IMAP requires that the connection be maintained between client and server continuously while working with mail, whereas POP3 enables the user to work with mail offline. Also, security is an issue with IMAP, as the remote client takes on the appearance of a remote virtual server. See also client, e-mail, IETF, POP3, RFC, server, and virtual server.