title: Have mule call http process that expects multipart/form-data
body: <p>I have a backend process that expects multipart/form-data. I'd like to have mule call it and return the results. Here is a simple flow that I've worked up. However, the outbound-endpoint doesn't transform the message into multipart/form-data. The backend process just gets the body that was initially posted in.</p>
  
  <p>What am I doing wrong?</p>
  
  <pre><code>&lt;flow name="testFlow"&gt;
      &lt;http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" mimeType="text/plain" contentType="text/plain" /&gt;
      &lt;message-properties-transformer&gt;
          &lt;add-message-property key="f" value="#[payload:java.lang.String]"/&gt;
      &lt;/message-properties-transformer&gt;
      &lt;http:outbound-endpoint exchange-pattern="request-response" host="x12backend" port="9877" path="dummy.php" contentType="multipart/form-data"/&gt;
  &lt;/flow&gt;
  </code></pre>