Mailboxes, distribution lists, and public folders are the most common addressable objects found in the Microsoft Exchange Server directory. These objects are accessed through the MAPI address book from both server- and client-based applications. For example, an application can supply a user’s name to the address book and retrieve the entry identifier for that user’s directory object. This entry identifier can then be used to obtain this user’s attributes, such as first and last name, department, phone number, and e-mail addresses.
MAPI address book functions are also used to write information to the directory and to create objects of selected classes in the directory. MAPI operates independently of the underlying directory service, so applications can work with any MAPI-compliant directory service. Most client applications use MAPI to look up information in the directory.