HI All In our environment we are seeing exception after upgrading the keycloak server version from 3.4 to 4.5 and enabling the event listener. 2019-04-09 06:25:43,325 ERROR [org.keycloak.services] (default task-6) KC-SERVICES0088: Failed to send execute actions email: org.keycloak.email.EmailException: javax.mail.AuthenticationFailedException: ; nested exception is: javax.mail.MessagingException: Exception reading response; nested exception is: java.net.SocketTimeoutException: Read timed out at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:145) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java :251) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java :246) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java :237) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java :197) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.sendExecuteActions(FreeMarkerEmailTemplat eProvider.java:163) at org.keycloak.services.resources.admin.UserResource.executeActionsEmail(UserResource.java:709) at org.keycloak.services.resources.admin.UserResource.sendVerifyEmail(UserResource.java:739) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) \ 2019-04-09 08:41:10,606 WARN [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffffac1f0dea:2f1df5ed:5cac520e:504 in state RUN 2019-04-09 08:41:10,608 WARN [com.arjuna.ats.arjuna] (Transaction Reaper Worker 0) ARJUNA012095: Abort of action id 0:ffffac1f0dea:2f1df5ed:5cac520e:504 invoked while multiple threads active within it. 2019-04-09 08:41:10,609 WARN [com.arjuna.ats.arjuna] (Transaction Reaper Worker 0) ARJUNA012381: Action id 0:ffffac1f0dea:2f1df5ed:5cac520e:504 completed with multiple threads - thread default task-11 was in progress with sun.misc.Unsafe.park(Native Method) java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer. java:2039) org.apache.http.pool.PoolEntryFuture.await(PoolEntryFuture.java:138) org.apache.http.pool.AbstractConnPool.getPoolEntryBlocking(AbstractConnPool.java:306) org.apache.http.pool.AbstractConnPool.access$000(AbstractConnPool.java:64) org.apache.http.pool.AbstractConnPool$2.getPoolEntry(AbstractConnPool.java:192) org.apache.http.pool.AbstractConnPool$2.getPoolEntry(AbstractConnPool.java:185) org.apache.http.pool.PoolEntryFuture.get(PoolEntryFuture.java:107) org.apache.http.impl.conn.PoolingHttpClientConnectionManager.leaseConnection(PoolingHttpClientConnectio nManager.java:276) org.apache.http.impl.conn.PoolingHttpClientConnectionManager$1.get(PoolingHttpClientConnectionManager.j ava:263) org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:190) org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184) org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88) org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110) org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184) org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82) org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107) org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55) com.nokia.csf.keycloak.notifications.HTTPJsonNotifier.send(HTTPJsonNotifier.java:42) com.nokia.csf.keycloak.notifications.URLCallBackNotification.process(URLCallBackNotification.java:47) com.nokia.csf.keycloak.providers.events.CSFGenericEventListenerProvider.onEvent(CSFGenericEventListener Provider.java:57) Regards SPS.Nathan