Message.confirm() doesn't work for remote channel destinations.

[krasserm]

Reason is that Message confirmation targets and messages are currently not serialized by MessageSerialization. Until this issue is fixed, applications should create a local destination proxy for a remote destination. The proxy confirms a message delivery when when it receives a reply from the remote destination:

class DestinationProxy(remoteDestination: ActorRef) extends Actor { this: Receiver =>
  implicit val timeout = Timeout(5 seconds)

  import context.dispatcher

  def receive = {
    case event => {
      val currentMessage = message
      remoteDestination ? event onComplete {
        case Success(_) => currentMessage.confirm(true)
        case Failure(_) => currentMessage.confirm(false)
      }
    }
  }
}