With IMAP, users access messages as though they were stored locally, when in fact that E-mail may be manipulated on a server miles away. Because it has that remote capability, IMAP is most likely to be adopted by corporate users who see roaming features as important, says Paul Hoffman, director of the Santa Cruz, Calif.-based Internet Mail Consortium, an industry group made up of vendors and users. IMAP lets them do that.
Users dial in to the server, and POP plops the messages into their in-box.
It then deletes that mail from the server. Both protocols have been around for more than 10 years. Users can apply mail filters and search agents on the server. And messages can be picked up from any machine, anywhere, Rassner says. But vendors have interpreted the ambiguous IMAP4 specification in different ways, which has led to inconsistencies among mail clients and servers, Rassner says.