title: Sending to Akka's Dead Letter Channel from many other actors in the fallback case
body: <p>New to both Scala + Akka here. I have a small network of actors that all send different messages to each other. Many of them need access to my <code>DeadLetterChannel</code> actor in case they receive a message that they are not sure how to handle:</p>
  
  <pre><code>class DeadLetterChannel(val queue : mutable.Queue[Any]) extends Actor with Logging {
    override def receive: Receive = {
      case any : Any =&gt;
        log.info(s"${this.getClass} just received a message of type ${} from ${sender().getClass}.")
        queue.enqueue(any)
      case _ =&gt;
        log.warn(s"${this.getClass} just received a non-Any message.")
    }
  }
  </code></pre>
  
  <p>Then from inside many other actors:</p>
  
  <pre><code>class DeviceManager(val dlc : DeadLetterChannel) extends ActorRef {
    override def receive: Receive = {
      case Heartbeat =&gt;
        // Handle Heartbeat here...
      case Connect:
        // Handle Connect here...
      case Disconnect:
        // Handle Disconnect here...
      case _ =&gt;
        dlc ! ???
    }
  }
  </code></pre>
  
  <p>I have two problems here:</p>
  
  <ul>
  <li>I'm getting a compiler error on the sending of the message (specifically the <code>!</code> overload: "<em>Cannot resolve symbol !</em>"); and</li>
  <li>I have no idea what to send to <code>dlc</code> in the <code>_</code> case, any ideas? Obviously I'm just trying to send the message that <code>DeviceManager</code> received that is neither a <code>Heartbeat</code>, a <code>Connect</code> or a <code>Disconnect</code> type</li>
  </ul>