Microsoft released the Exchange Web Services (EWS) Managed API 1.0 Beta provides a managed interface for developing client applications that use Exchange Web Services. The EWS Managed API simplifies the implementation of applications that communicate with Microsoft Exchange Server 2007 Service Pack 1 (SP1) and later versions of Microsoft Exchange. Built on the Exchange Web Services SOAP protocol and Autodiscover, the EWS Managed API provides a .NET interface to EWS that is easy to learn, use, and maintain.

More info: Download | Introducing the Exchange Web Services Managed API 1.0