title: Cann't Get SourceUrl's attachment from outlook REST API
body: <p>According to <a href="https://msdn.microsoft.com/office/office365/APi/mail-rest-operations#get-attachments" rel="nofollow noreferrer">Outlook Mail REST API reference</a> I should be able to get 
  <code>SourceUrl</code> property by calling:
  <br></p>
  
  <pre><code>`GET https://outlook.office.com/api/beta/me/messages/{messageId}/attachments/{attachmentId}`
  </code></pre>
  
  <p><br>
  or
  <br></p>
  
  <pre><code>`GET https://outlook.office.com/api/beta/me/messages/{messageId}/?$expand=attachments`
  </code></pre>
  
  <p><br>
  in both of version 2.0 and beta but <code>SourceUrl</code> is always missing,
  <br><br>
  do I need any additional information to get it? knowing that I'm not getting any error!
  <br><br>
  Thanks</p>