Messaging Application Programming Interface (MAPI) defines a complete architecture for messaging applications, which allows client programs to become (e-mail) messaging-enabled, -aware, or -based by calling MAPI subsystem routines that interface with certain messaging systems and message stores. The MAPI architecture can be used for e-mail, scheduling, personal information managers, bulletin boards, and online services that run on mainframes, personal computers, and hand-held computing devices. The comprehensive architectural design allows MAPI to serve as the basis for a common information exchange.

MAPI is made up of a set of common application programming interfaces and a dynamic-link library (DLL) component. The interfaces are used to create and access diverse messaging applications and messaging systems, offering a uniform environment for development and use and providing true independence for both.

Under MAPI architecture, to use the messaging services, a client must first establish a session. A session is a specific connection between the client and the MAPI interface based on information provided in a profile.After establishing a MAPI session, the client can use the MAPI services. MAPI defines three primary services: address books, transports, and message stores.

• Address book: A persistent database that contains valid addressing information.
• Transport: supports communication between different devices and different underlying messaging systems.
• A message store: stores messages in a hierarchical structure that consists of one or more folders.

A message in MAPI represents a communication that is sent from the sender to one or more recipients or that gets posted in a public folder. A message can include one or more attachments. The message can have one or more recipients. A recipient can be an individual or a distribution list.

MAPI was originally designed by Microsoft. MAPI was the main e-mail data access method used by Microsoft until Exchange 5.5, by the Exchange Data Objects (EDO) and Collaboration Data Objects (CDO) interfaces. Exchange 2000 greatly expanded the supported services, notably with MAPI-compliant LDAP. Simple MAPI and CMC were removed from Exchange 2003.

MAPI: Messaging Application Programming Interface

Related Terms: Email, LDAP, Microsoft Exchange

Reference Links: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/
mapi/html/_mapi1book_mapi_programming_basics.asp : MAPI Program Basics