title: Mule - Outbound Attachments lost in Http response
body: <p>I added an Attachment transformer to set an attachment and expected it will be delivered in the HTTP response. However I only see the payload string set in the flow. </p>
  
  <pre><code>&lt;flow name="nonrestdownloadFlow1" doc:name="nonrestdownloadFlow1"&gt;
          &lt;http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8083" doc:name="HTTP"/&gt;
          &lt;set-attachment attachmentName="attachment.txt" value="dfsdkgnsgjkdfgjkdrng05305fgkgnkdfngkng04t04tkdgndjkgni" contentType="text/plain" doc:name="Add Attachment"/&gt;
         &lt;set-property propertyName="Content-Type" value="multipart/form-data" doc:name="Add content type"/&gt;
          &lt;set-payload doc:name="Set Payload" value="Hello, see attachment with this response"/&gt;
          &lt;logger level="INFO" doc:name="Logger"/&gt;
      &lt;/flow&gt;
  </code></pre>
  
  <p>What am i missing? Can someone help me understand please </p>
  
  <p>Thanks
  Venkat</p>