What is the correct configuration for Notifications/Escalation of Human Tasks?

Issue

I am trying to achieve task notification email functionality.

I have designed a process with human task and a "not-started" notification to it Expiry at 1m.

In EAP 6.2 I have created a new mail session jbpmMailSession as below:

        <mail-session jndi-name="java:jboss/mail/jbpmMailSession">
            <smtp-server outbound-socket-binding-ref="iht-smtp">
                <login name="DataAcquisitionAdmin@customer.com" password="Password" />
            </smtp-server>
        </mail-session>

I have also created remote-destination as below:
<socket-binding-group

    <outbound-socket-binding name="iht-smtp">
        <remote-destination host="ihtmail.customer.com" port="25"/>
    </outbound-socket-binding>

Once I started process, After 1 minute (Notification Expiry) passed from creation of task, I see below logs:

18:39:41,480 WARN [org.jbpm.services.task.deadlines.notifications.impl.email.EmailSessionProducer] (pool-18-thread-1) Mail session was not found in JNDI under mail/jbpmMailSession trying to look up email.properties on classspath
18:39:41,483 ERROR [org.jbpm.services.task.deadlines.notifications.impl.email.EmailSessionProducer] (pool-18-thread-1) email.properties was not found on classpath, nor mail session available in JNDI, unable to configure deadlines
18:39:41,721 ERROR [org.jbpm.services.task.deadlines.notifications.impl.email.EmailNotificationListener] (pool-18-thread-1) Cannot proceed with notifications as not all requirements are meet - mail session or userinfo is not available.

What is that Iam missing here?