Unified Messaging Web Service Reference
The Unified Messaging Web service provides an extensibility point that enables clients to read and change information about Unified Messaging properties. This reference section contains information about the operations and elements that make up the XML messages for the Unified Messaging Web service.
For Microsoft Exchange Server 2010 and later versions, we recommend that you use the Unified Messaging operations that are available in Exchange Web Services (EWS) instead of the Unified Messaging Web service, for the following reasons:
A sample WSDL that describes the legacy Unified Messaging endpoint can be found in the Samples\UMWebService folder in the downloadable SDK.