Using Client Extensions

Microsoft Exchange Server client extensions allow you to add functionality to the user interface with limited development effort.

Extending the Microsoft Exchange Client usually involves adding functionality to the Viewer, the main window in the Microsoft Exchange Client. The Viewer is the user's primary interface, where users access, organize, and exchange information. The Viewer groups all kinds of information in one place, including such diverse objects as e-mail messages, word-processing documents, voice mail, faxes, spreadsheets, presentation graphics, meeting requests, and customer contact reports. The toolbar is the interface for tasks such as printing, creating a new message, deleting an item, or viewing the address book.

Using client extensions to expose application-specific functionality is usually appropriate when one or more of the following conditions is satisfied:

• The application adds to the core capabilities of Microsoft Exchange Server, rather than uses Microsoft Exchange Server as a mechanism to deliver completely separate functionality.
• The new features are used in the context of a particular message or folder in the Microsoft Exchange Server information store.

Typical client extensions include custom menu commands, customized event handling, supplied advanced search criteria, and the addition of a new pane to the Viewer window.

For more information about developing client extensions, see "Extending the Microsoft Exchange Client" in the "Database and Messaging Services" section of the Microsoft Platform SDK.