如何在Scala Actors中实现邮箱(消息队列)？

libraryDependencies += "com.typesafe.akka" %% "akka-actor" % "2.6.17"

import akka.actor.Actor
import akka.actor.ActorRef
import akka.actor.Props

class MailboxActor(receiver: ActorRef) extends Actor {
  var messages: List[String] = List.empty

  def receive: Receive = {
    case message: String =>
      messages = message :: messages
      receiver ! message
  }
}

import akka.actor.Actor

class ReceiverActor extends Actor {
  def receive: Receive = {
    case message: String =>
      println(s"Received message: $message")
  }
}

import akka.actor.ActorSystem

object Main extends App {
  val system = ActorSystem("MailboxSystem")

  val receiver = system.actorOf(Props[ReceiverActor], "ReceiverActor")
  val mailbox = system.actorOf(Props(classOf[MailboxActor], receiver), "MailboxActor")

  mailbox ! "Hello, Akka!"
}