title: What are the file extensions of various Ews/Outlook items?
body: <p>I need to save ItemAttachments retrieved using EWS API but I don't know file extension of all the different item types.I could only manage to get the extension of item of type EmailMessage and Contact. Here is the code. </p>
  
  <pre><code>if (attachment is ItemAttachment)
  {
      var itemAttachment = attachment as ItemAttachment;
  
      itemAttachment.Load(new PropertySet(ItemSchema.MimeContent));
  
      var fileExtension = "";
  
      if (itemAttachment.Item is EmailMessage)
      {
          fileExtension = ".eml";
      }
      else if (itemAttachment.Item is PostItem)
      {
          fileExtension =??  
      }
      else if (itemAttachment.Item is Contact)
      {
          fileExtension = ".vcf";
      }
      else if (itemAttachment.Item is ContactGroup)
      {
          fileExtension =??
      }
      else if (itemAttachment.Item is Appointment)
      {
          fileExtension = ??
      }
      else if (itemAttachment.Item is Task)
      {
          fileExtension = ??
      }
  }
  </code></pre>
  
  <p>Can somebody tell me what are the file extensions of rest of the items?? </p>