ClassCastException: javax.mail.Session incompatible with javax.mail.Session

Issue

When trying to send an email from business process, deployed on the kie-server.war the following exceptions occurs:

Caused by: org.jbpm.bpmn2.handler.WorkItemHandlerRuntimeException: java.lang.ClassCastException: javax.mail.Session incompatible with javax.mail.Session
    at org.jbpm.process.workitem.AbstractLogOrThrowWorkItemHandler.handleException(AbstractLogOrThrowWorkItemHandler.java:55)
    at org.jbpm.process.workitem.AbstractLogOrThrowWorkItemHandler.handleException(AbstractLogOrThrowWorkItemHandler.java:38)
    at org.jbpm.process.workitem.email.EmailWorkItemHandler.executeWorkItem(EmailWorkItemHandler.java:88)
    at org.drools.persistence.jpa.processinstance.JPAWorkItemManager.internalExecuteWorkItem(JPAWorkItemManager.java:69)
    at org.jbpm.workflow.instance.node.WorkItemNodeInstance.internalTrigger(WorkItemNodeInstance.java:138)
    ... 107 more
Caused by: java.lang.ClassCastException: javax.mail.Session incompatible with javax.mail.Session
    at org.jbpm.process.workitem.email.SendHtml.getSession(SendHtml.java:189)
    at org.jbpm.process.workitem.email.SendHtml.sendHtml(SendHtml.java:68)
    at org.jbpm.process.workitem.email.SendHtml.sendHtml(SendHtml.java:55)
    at org.jbpm.process.workitem.email.EmailWorkItemHandler.executeWorkItem(EmailWorkItemHandler.java:82)
    ... 109 more