Internet Message Access Protocol (IMAP) was developed from a need for mobile email access. Many workers read mail from a variety of locations (the office, home, hotel rooms, and so on) and want such flexible features as the ability to download headers first and then selectively download mail messages. The main mail delivery protocols before IMAP, for the Internet, was POP, which offers more rudimentary mail delivery-only functionality
With IMAP, traveling users can access their email from anywhere and download it or leave it on the server as desired. POP, on the other hand, does not work well when users access email from many different machines; users end up with their email distributed across many different email clients. IMAP provides users with the ability to remotely manage multiple email boxes, and store or search as well as archive old messages.