debc5e21_Activiti_User_Guide_Table_1__Supported_events_Event_name
[Description] An activity received a message. Dispatched before the activity receives the message. When received, a ACTIVITY_SIGNAL or ACTIVITY_STARTED will be dispatched for this activity, depending on the type (boundary-event or event-subprocess start-event) [Event classes] org.activiti…​ActivitiMessageEvent [Event name] 
ACTIVITY_MESSAGE_RECEIVED
Activiti User Guide
Event name