01:12:11,563 AM [testsystem-akka.actor.default-dispatcher-7] [INFO] RepointableActorRef -  akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-30#-1510891984] to Actor[akka://testsystem/user/pingpongactor#-1660203977] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#-1660203977] 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'.