title: How to set Azure retry policy exceptions?
body: <p>I have set retry policy in Azure APIM to track 503 errors. </p>
  
  <pre><code>&lt;backend&gt;
      &lt;retry condition="@(context.Response.StatusCode == 503)" count="3" interval="5" first-fast-retry="true"&gt;
          &lt;forward-request buffer-request-body="true" /&gt;
      &lt;/retry&gt;
  &lt;/backend&gt;
  </code></pre>
  
  <p>When backend api has connectivity issue, we try 3 times and then give up the retry.</p>
  
  <p>This works great however eventhough the internal error is caught as 503, we get 500 Internal server error as response. </p>
  
  <p>How do we get correct return code as 503 in outbound ?</p>