NMapi is an 100% managed C# implementation of the NMapi API for the .NET Framework and Mono. In addition to the MAPI API it also provides a pluggable backend architecture as well as a high-level abstraction of MAPI based on smart C# objects and a custom high-performance LINQ-Implementation.

It also is the foundation for other openmapi.org components like the OpenMapi.org Proxy Server.