You can get the MAPI reference for Outlook 2010 using MSDN: http://msdn.microsoft.com/en-us/library/cc765775(office.14).aspx
MAPI for Outlook 2010 provides a set of interfaces, functions, and other data types to facilitate the development of Outlook 2010 messaging applications. Applications and transports use MAPI to manipulate e-mail data, to create e-mail messages and the folders to store them in, and to support notifications of changes to existing MAPI-related data.
Something related, that if you’re interested and want to try to use…
- Getting Started with the Outlook 2010 MAPI Reference: Provides information about the various reference and conceptual resources in the Outlook 2010 MAPI Reference.
- MAPI Samples : Provides sample applications.
- MAPI Concepts: Provides a guide to understanding and programming with MAPI.
- MAPI Reference : Provides references to MAPI programming elements