MAPI (Messaging Application Programming Interface)

MAPI (Messaging Application Programming Interface) is a messaging architecture allows clients programs to become email messaging-enabled (or messaging-based) by calling MAPI subsystem routines that interface with certain messaging servers. While MAPI is designed to be independent of the protocol, it is usually used with MAPI over HTTP or MAPI/RPC, protocols used by Microsoft Outlook to communicate with Microsoft Exchange Server.
MAPI-compatible applications typically include a Send Mail or Send in the File pulldown menu of the application. Selecting one of these sends a request to a MAPI server.

MAPI Advantages:

1. IMAP supports both on-line and off-line modes of operation.
2. E-mail clients using IMAP generally leave messages on the server until the user explicitly deletes them.
3. Allow multiple clients to manage the same mailbox.
4. Provides faster reconnection times after a communications break
5. 70% faster connection to Exchange.
6. Enables future innovation in authentication by using an HTTP based protocol, such as MFA.