(feat) can now send out MDN responses

UI/WebServerResources/js/Mailer/Message.service.js

@@ -310,6 +310,16 @@
     });
   };
 
+  /**
+   * @function $sendMDN
+   * @memberof Message.prototype
+   * @desc Send MDN response for current email message
+   */
+  Message.prototype.$sendMDN = function() {
+    this.shouldAskReceipt = 0;
+    return Message.$$resource.post(this.id, 'sendMDN');
+  }
+
   /**
    * @function $deleteAttachment
    * @memberof Message.prototype