title: InvalidSenderError: Unauthorized sender (Google App Engine)
body: <p>The <a href="http://code.google.com/appengine/docs/python/mail/overview.html" rel="nofollow">documentation</a> states:</p>
  
  <blockquote>
    <p>The From: address can be the email
    address of a registered administrator
    (developer) of the application, the
    <strong>current user</strong> if signed in with Google
    Accounts...</p>
  </blockquote>
  
  <p>This works fine for my app when the current user's Google Account happens to be a Gmail account. It used to work fine for non-Gmail google accounts also but of late I see an error:InvalidSenderError: Unauthorized sender
  for non-Gmail google accounts. Am I missing any recent changes to the implementation?</p>