ActorDI.scala

case class ReportInvalidJsonActorHolder(ref: ActorRef)
case class ReportUnhandledExceptionActorHolder(ref: ActorRef)
case class HeartbestProcessingActorHolder(ref: ActorRef)
case class DebugEmailActorHolder(ref: ActorRef)

object ReportInvalidJsonActor {
  def props(debugEmailActorHolder: DebugEmailActorHolder) =
    Props(classOf[ReportInvalidJsonActor], debugEmailActorHolder)
  
  case class InvalidJsonMessage(content : String, exceptionMessage: String)
}

class ReportInvalidJsonActor(debugEmailActorHolder: DebugEmailActorHolder) extends Actor {

  override def receive = {
    case m : InvalidJsonMessage => debugEmailActorHolder.ref ! DebugEmailActor.EmailMessage(...)
}}


@Singleton
class ReportInvalidJsonActorProvider @Inject() (
  system: ActorSystem,
  debugEmailActorHolder: DebugEmailActorHolder) extends Provider[ReportInvalidJsonActorHolder] {

  def get: ActorRef = {
    val ref = system.actorOf(ReportInvalidJsonActor.props(debugEmailActorHolder), "report-invalid-json")
    ReportInvalidJsonActorHolder(ref)
  }

}

LGTM