What Is Messaging Application Programming Interface – Messaging Application Programming Interface (MAPI) is a messaging architecture and component-based API Model for Microsoft Windows. MAPI allows client programs to be (e-mail) capable of messaging, realizing, or based by calling the MAPI subsystem routines that interact with specific message servers. While MAPI is designed to be free of protocols, it is commonly used with MAPI / RPC, a proprietary protocol that Microsoft Outlook uses to communicate with Microsoft Exchange. See Also: What is Email Service Provider
MAPI uses the functionality loosely based on the X.400 XAFIA standard. This includes the facility to access message transport, message stores, and directories.
While Simple MAPI (SMAPI) is a subset of 12 functions that allow developers to add basic messaging functions, Extended MAPI (EMAPI) allows full control over the messaging system on client computers. This includes message creation and management, plus client mailbox management, and service providers.
Simple MAPI ships with Microsoft Windows as part of Outlook Express / Windows Mail while MAPI Extended ships are full of Office Outlook and Exchange. What is Webmail
In addition to the Extended MAPI client interface, programming calls can be made indirectly via the Simple MAPI API client interface, through the API General API (API) API interface interface, or by the object-based CDO Library interface. These three methods are easier to use and are designed for less complex messaging-enabled and-aware applications. (Simple MAPI and CMC have been removed from Exchange 2003.)
MAPI was originally designed by Microsoft. The company founded its MS Mail team in 1987, but it was not until Consumer Software was acquired in 1991 to get Network Courier that has a messaging product. Reprocessed, it is sold as MS PC Mail (or Microsoft Mail for PC Networking). The basic API for MS PC Mail is later known as MAPI version 0 (or MAPI0), to distinguish it from “real” MAPI.
Service provider interface
The complete MAPI Extended interface is required to connect message-based services to client applications such as Outlook. For example, some non-Microsoft e-mail server product vendors create “MAPI service providers” to allow their products to be accessed through Outlook. Important examples include Axigen Mail Server, Kerio Connect, Scalix, Zimbra, HP OpenMail, IBM Lotus Notes, Zarafa / Kopano, and Bynari.
MAPI also has a service provider interface. Microsoft uses this to interface MS Mail to Xenix-based email systems, for internal use.
Extended MAPI is the primary e-mail access method used by Outlook, to interface to Microsoft Exchange, through the MAPI service providers that are shipped with Outlook.
Details of MAPI / RPC protocol
Microsoft has released full details of the MAPI / RPC protocol since August 2007.
“MAPI Protocol” is the everyday name for MAPI / RPC. Sometimes, Microsoft also calls it “Exchange RPC” and “Outlook-Exchange Transport Protocol”. See Also: What is Email Hosting Service
Microsoft provides an example of a MAPI / RPC-based application called MFCMAPI to help developers. It’s also widely used as a diagnostic tool by Microsoft Exchange developers and administrators.
There are at least three open source projects that start implementing the MAPI protocol in a free open source software library (FOSS) for use in other open-source applications:
Zarafa / Kopano MAPI4Linux (also part of OpenMapi)
The libmapi subproject of the OpenChange project, which is used in another OpenChange subproject called Evolution-MAPI. Evolution-MAPI is a provider of connectors that can be installed inside an open source Evolution groupware client.