Are you talking about the listener defined in the ServiceNow Platform?  If so I suspect you could create a business rule on the table for the listener record (ecc_agent_ext_context_trap).  If the status changes to 'stopped', you could have the business rule trigger an Event in the ServiceNow Events table.  Notifications can be triggered by events and that notification could be sent to any group/user defined (via the user/group's email address).

Mid Server Listener

https://docs.servicenow.com/bundle/newyork-it-operations-management/page/product/event-management/ta...

 

In the business rule you could raise an Event using gs.eventQueue(eventname,current,parm1,parm2);

In this example it could be:

gs.eventQueue(mid.server.listener.down,current,current.mid_server.name,current.status);

Then you would need to add a record referencing the event name in the Event Registry table. Finally you could then use that Event as a trigger for Notifications.

 

Does this make sense?