1. Need to change configuration also for that …pl check path below .

(Activiti Server Folder)\webapps\activiti-rest\WEB-INF\classes\activiti-context.xml

—–Change Property from False to True

    <property name=”jobExecutorActivate” value=”true” />

—Add New Property

<property name=”mailServerHost” value=”xxx.gmail.com” />
<property name=”mailServerPort” value=”25″ />
<property name=”mailServerUseTLS” value=”true” />
<property name=”mailServerDefaultFrom” value=”xxx@yyy.com” />
<property name=”mailServerUsername” value=”xx@yy.com” />
<property name=”mailServerPassword” value=”xxxx” />

After that Pl stop and start activiti server

2. download escalation bpmn here