Microsoft Exchange Server 2007 with SP1

7.8 Internet Client Access Protocols

MAPI is the most functional client access protocol for Exchange, but access via MAPI is limited to clients produced by Microsoft (Outlook). If you want to use a non-MAPI client to access Exchange that is not a web browser, you have to use one of the Internet client access protocols supported by Exchange: POP3 (Post Office Protocol version 3) or IMAP4 (Internet Mail Access Protocol version 4). These protocols allow you to accommodate clients on non-Microsoft platforms, such as Linux, UNIX, and Macintosh¹⁵ as well as handheld clients that cannot connect to Exchange via ActiveSync. IMAP4 is the more functional access protocol and it is the one that is most used today. POP3 is a throwback to a simpler time for ...