title: Am getting invalid XML as a response from EWS calls?
body: <p>Am using EWS API to connect Exchange server. The connection was established, but I didn’t receive any response.</p>
  
  <p>Am getting exception “The response received from the service didn't contain valid XML.” </p>
  
  <p>The inner Exception was “DTD is prohibited in this XML document.”  </p>
  
  <p>I didn’t get what is DTD?</p>