12:43:37,487 AM [testsystem-akka.actor.default-dispatcher-6] [INFO] RepointableActorRef -  akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-30#1713305309] to Actor[akka://testsystem/user/pingpongactor#1991001480] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#1991001480] 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'.