Want to get and install MAPI header and library files? MAPI header and library files are included as part of the Microsoft Windows SDK. Once you have installed Microsoft Windows SDK, you can access MAPI header files by using Microsoft Visual Studio 2008.

Before you can install MAPI header and library files, make sure that you have met the following prerequisite -You have a supported Windows-based operating system installed and running on your computer.

To install MAPI header and library files, you can try either one of the following steps:
  1. Download and install Microsoft Windows SDK.

  2. Obtain and install Microsoft Visual Studio 2005 or a later version (optional).
    Note: Windows SDK is installed to \Program Files\Microsoft SDKs\Windows as a component of Visual Studio.

After following these steps, you can view the MAPI header and library files in the following locations. The MAPI header files are located at <drive>\Program Files\Microsoft SDKs\Windows\<SDK_Version>\Include. The MAPI library file Mapi32.lib is located at <drive>\Program Files\Microsoft SDKs\Windows\<SDK_Version>\Lib.

Related info:

SGriffin's MAPI Internals: Outlook 2010 MAPI Reference
Outlook 2010: MAPI Header Files.
For a list of MAPI header files, see Finding Header Information.
How to: Link to MAPI functions, refer http://msdn.microsoft.com/en-us/library/cc963763(v=office.12).aspx
Mapi32.dll Stub Registry Settings
Setting Up the MSI Keys for Your MAPI DLL
Explicitly Mapping MAPI Calls to MAPI DLLs