A Microsoft technology that allows developers to use the Microsoft Windows messaging subsystem for writing messaging applications.
Messaging Application Programming Interface (MAPI) provides a generic programming interface for making Windows applications mail-enabled and standardizes how messages are handled by messaging applications. MAPI also provides a general messaging subsystem built into the Windows operating system that can function with any message transport mechanism.
The messaging subsystem is thus similar to the printing subsystem that allows Windows to interface with any kind of print device and perform standard printing functions.
MAPI is a kind of middleman between the messaging application running on the computer and the underlying messaging services. The client interface for accessing these services through MAPI is the same whether the services are LAN-based messaging services, e-mail services, fax services, or any other messaging service.
MAPI allows standard function calls to access general messaging functions such as sending, receiving, and reading messages in a uniform fashion regardless of the messaging subsystem used.
MAPI provides two sets of interfaces: the client-side application programming interfaces (APIs) called by the messaging application, and the service-provider interfaces that the Windows messaging subsystem uses to connect with different messaging-handling systems.
Microsoft Outlook is an example of a MAPI-enabled client. Microsoft Exchange Server is Microsoft’s MAPI-enabled mail server.