You can perform most directory tasks using either MAPI functions or directory access functions. Each of these sets of functions has its own advantages and its own dependencies.
For example, the directory access functions are specific to Microsoft Exchange Server. They run only on Windows NT Server computers on which the Microsoft Exchange Server Administrator program has been installed. Because directory access DLLs are not installed on client computers, you must use MAPI for all directory access activities performed by client applications, including those running on Windows 95 clients.
In contrast, MAPI is independent of the underlying directory service, which enables your program to work with any MAPI-compliant directory service.
For these reasons, you should typically use MAPI to manipulate directory objects. But certain other aspects of common directory operations should be considered, as discussed in the following sections.