Welcome to the Outlook Auxiliary Reference

The Outlook Auxiliary Reference contains conceptual content and reference documentation for four sets of APIs, code samples, and a redistributable installer that allow developers to extend and integrate with Outlook. APIs in this reference are exposed by Outlook for extensibility, outside of the Outlook object model.

If you are new to developing solutions for Outlook, see Selecting an API or technology for developing solutions for Outlook to identify the APIs and technologies that are most appropriate for your needs.

For specific information about the Outlook object model, see the Outlook VBA reference.

For specific information about Messaging API (MAPI) supported by Outlook, see the Outlook MAPI Reference.

Conceptual

The conceptual discussion includes the following subjects:

Reference

The reference content includes the following:

  • The APIs Exported by Outlook include functions and data structures that were originally implemented for internal use and are now exposed for public use.

  • The Account Management API provides access to user account information and notifications of account changes.

  • The Data Degradation Layer API supports clients that access an Outlook item in a preferred character format rather than the object's native character format.

  • The Free/Busy API provides free/busy status information about specific user accounts within a specific time range.

Sample tasks

Sample how-to tasks in the Outlook Auxiliary Reference include the following:

The reference for each API lists the constants, type definitions, and interfaces that a developer must implement to use the additional functionality.

Note

Developers must implement these APIs only as documented in this reference. Certain interface members and method parameters are named as placeholders because they are reserved for the internal use of Outlook and are subject to change without notice.