12:42:32,896 AM [testsystem-akka.actor.default-dispatcher-6] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason] 12:42:32,901 AM [testsystem-akka.actor.default-dispatcher-6] [INFO] RepointableActorRef - akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-30#-1594112900] to Actor[akka://testsystem/user/pingpongactor#710777572] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#710777572] may have terminated unexpectedly. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.