Internet Message Access Protocol version 4 (IMAP4) is a message retrieval protocol similar to POP3. IMAP4, however, offers several new features that aren't available with POP3. With IMAP4, you can browse server-based folders and move, delete, and view messages without first copying the messages to your local computer. IMAP4 also allows you to save certain settings such as client window appearance or search messages on the server for a specified search string. You can also create, remove, and rename mailboxes on the server computer.