title: Gmail API returns 403 forbidden and no other messages (other API's working fine)
body: <p>I've got an application with several successful Google API integrations. I'm hitting a roadblock trying to add Gmail integration into the mix. I'm using the .NET API, Google.Apis.Gmail.v1 (version 1.9.0.140).</p>
  
  <p>Here's my code showing a successful Drive API call followed by the Gmail API call that fails:</p>
  
  <pre><code>var drive = new DriveService(Context.GoogleOAuthInitializer);
  var list = drive.Files.List().Execute();
  Console.WriteLine(list.Items.Count);
  // Output: 100 (first page of results)
  
  var gmail = new GmailService(Context.GoogleOAuthInitializer);
  var result = gmail.Users.Drafts.List("me").Execute();
  // Throws exception described below
  </code></pre>
  
  <p>The .NET exception provides this information:</p>
  
  <pre><code>Google.Apis.Requests.RequestError
  Forbidden [403]
  Errors [
      Message[Forbidden] Location[ - ] Reason[forbidden] Domain[global]
  ]
  </code></pre>
  
  <p>I'm using the following scopes to get the OAuth token. When I added the gmail scope, I was (as expected) prompted again by Google, "Do you want to give this application access to your email?" I also enabled the gmail API in the Google API Console.</p>
  
  <pre><code>https://www.google.com/m8/feeds
  https://www.googleapis.com/auth/drive
  https://www.googleapis.com/auth/cloudprint
  https://www.googleapis.com/auth/userinfo.email
  https://mail.google.com/
      * https://www.googleapis.com/auth/gmail.compose was tried as well
  </code></pre>
  
  <p>Really wish there was something more helpful in the message to point me in the right direction!!!</p>