title: Why can I not add to the authorised email senders list under app engine settings
body: <p>My domain name is hosted by app engine and configured under:</p>
  
  <pre><code>App Engine -&gt; Settings -&gt; Custom domains
  </code></pre>
  
  <p>So why can I not add an email address to the authorised senders list:</p>
  
  <pre><code>App Engine -&gt; Settings -&gt; Email senders -&gt; Authorised senders
  </code></pre>
  
  <p>When I try to add an email address like: <code>noreply@mydomain.com</code>, I get an error dialog telling me that the email address does not exist. </p>
  
  <p>The email address does exist and works perfectly well.</p>
  
  <p>Am I missing something? Where exactly should the email 'exist' for example. I've read and reread the documentation on this but it seems to me that this should work.</p>
  
  <p>Thanks for any advice. </p>