Using Exchange Web Services Proxy Classes
You can use Visual Studio to develop Exchange Web Services client applications. Visual Studio and the Microsoft .NET Framework provide a set of tools that you can use to create Web services client applications. Visual Studio provides a tool named wsdl.exe that is used to create proxy classes in C# or VB.NET. Web services proxy classes act as an interface for client/Web server communications. The proxy classes provide user-friendly abstractions of the XML messages, XML serialization, and formation of the HTTP requests and responses that are sent between the client and server. The .NET Framework provides classes that are used to create and read SOAP messages. These classes provide access to the XML DOM and XML readers/writers.
For Exchange 2010 and later versions, we strongly recommend that you use the EWS Managed API instead of auto-generated proxies for developing against Exchange Web Services. The EWS Managed API object model is significantly easier to use than auto-generated proxy object models. For more information about the EWS Managed API, see Using the Exchange Web Services Managed API.