Each of the applications described above is made possible by the Mail Application Programming Interface (MAPI). It is an interrelated set of mail services in his or her application. It exists at the function level, i.e. MAPI is implemented as a dynamic-link library (DLL) with functions that must be declared within the application that calls them.
This paper addresses a subset of full MAPI often referred to as Simple MAPI. Simple MAPI contains all the functionality needed to implement useful mail-based applications within Microsoft Office.
Simple MAPI provides the following general categories of services: