Unable to send mail to contributors. Null pointer is dereferenced. oracle wcc 12.2.1.3

i run a work flow on oracle ucm 12.2.1.3

and when clicking on approve or eject following error appear|

how can disable the email Issue I have no local Mail Server and I want to Disable or Skip this step for now

!csUserEventMessage,weblogic,CIS!$!syNullPointerException

intradoc.common.ServiceException: 

*ScriptStack WORKFLOW_APPROVE_SUB

3:doSubService,dID=7WORKFLOW_APPROVE_SUB,dID=73:updateWorkflowAndDocState,dID=7,dDocName=ARPC0000000000000006

    at intradoc.server.workflow.WorkflowStates.moveToNextStep(WorkflowStates.java:1501)

    at intradoc.server.workflow.WorkflowStates.advanceWorkflowState(WorkflowStates.java:967)

    at intradoc.server.workflow.WorkflowStates.advanceDocumentStateImplement(WorkflowStates.java:685)

    at intradoc.server.workflow.WorkflowStates.advanceDocumentState(WorkflowStates.java:551)

    at intradoc.server.DocStateTransition.advanceDocumentState(DocStateTransition.java:75)

    at intradoc.server.workflow.WorkflowHandler.updateWorkflowAndDocState(WorkflowHandler.java:612)

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

    at java.lang.reflect.Method.invoke(Method.java:498)

    at intradoc.common.IdcMethodHolder.invokeMethod(IdcMethodHolder.java:86)

    at intradoc.common.ClassHelperUtils.executeMethodReportStatus(ClassHelperUtils.java:324)

    at intradoc.server.ServiceHandler.executeAction(ServiceHandler.java:79)

    at intradoc.server.workflow.WorkflowHandler.executeAction(WorkflowHandler.java:133)

    at intradoc.server.Service.doCodeEx(Service.java:627)

    at intradoc.server.Service.doCode(Service.java:599)

    at intradoc.server.ServiceRequestImplementor.doAction(ServiceRequestImplementor.java:1813)

    at intradoc.server.Service.doAction(Service.java:571)

    at intradoc.server.ServiceRequestImplementor.doActions(ServiceRequestImplementor.java:1587)

    at intradoc.server.Service.doActions(Service.java:566)

    at intradoc.server.ServiceRequestImplementor.executeSubServiceCode(ServiceRequestImplementor.java:1450)

    at intradoc.server.Service.executeSubServiceCode(Service.java:4229)

    at intradoc.server.ServiceRequestImplementor.executeServiceEx(ServiceRequestImplementor.java:1326)

    at intradoc.server.Service.executeServiceEx(Service.java:4224)

    at intradoc.server.Service.executeService(Service.java:4208)

    at intradoc.server.Service.doSubService(Service.java:4118)

    at sun.reflect.GeneratedMethodAccessor749.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

    at java.lang.reflect.Method.invoke(Method.java:498)

    at intradoc.common.IdcMethodHolder.invokeMethod(IdcMethodHolder.java:86)

    at intradoc.common.ClassHelperUtils.executeMethodEx(ClassHelperUtils.java:310)

    at intradoc.common.ClassHelperUtils.executeMethod(ClassHelperUtils.java:295)

    at intradoc.server.Service.doCodeEx(Service.java:644)

    at intradoc.server.Service.doCode(Service.java:599)

    at intradoc.server.ServiceRequestImplementor.doAction(ServiceRequestImplementor.java:1813)

    at intradoc.server.Service.doAction(Service.java:571)

    at intradoc.server.ServiceRequestImplementor.doActions(ServiceRequestImplementor.java:1587)

    at intradoc.server.Service.doActions(Service.java:566)

    at intradoc.server.ServiceRequestImplementor.executeActions(ServiceRequestImplementor.java:1519)

    at intradoc.server.Service.executeActions(Service.java:552)

    at intradoc.server.ServiceRequestImplementor.doRequest(ServiceRequestImplementor.java:763)

    at intradoc.server.Service.doRequest(Service.java:2007)

    at intradoc.server.ServiceManager.processCommand(ServiceManager.java:520)

    at intradoc.server.IdcServerThread.processRequest(IdcServerThread.java:359)

    at intradoc.server.IdcServerThread.run(IdcServerThread.java:219)

    at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:670)

    at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:352)

    at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:337)

    at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:57)

    at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)

    at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:644)

    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:415)

    at weblogic.work.ExecuteThread.run(ExecuteThread.java:355)

Caused by: java.lang.NullPointerException

    at intradoc.server.workflow.WorkflowStates.addMailToQueue(WorkflowStates.java:2584)

    at intradoc.server.workflow.WorkflowStates.cleanUp(WorkflowStates.java:1731)

    at intradoc.server.workflow.WorkflowStates.moveToNextStep(WorkflowStates.java:1471)