MOSS 2007 is .net 2.0.. I found this DLL Microsoft.Exchange.WebServices.dll and moved it to my bin and added this to web.config
SafeControl Assembly="Microsoft.Exchange.WebServices, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" Namespace="Microsoft.Exchange.WebServices" TypeName="*" Safe="True"
But can't seem to introduce it into SharePoint 2007 without get this error:
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Runtime.InteropServices.COMException: Cannot complete this action.