I know what you mean,
Polling SNMP or WBEM os a whole other thing (pull) than pushing event using SNMP or WBEM. The push events (traps) generate events in SIM. Do you see events under your server(s) or under all events?
If the status changes it changes because off polling, events occur when traps are received. You can test this when you send a test trap from one of your servers. You should get an event if the traps are configured correctly.
If you see events see if you use the right event collection for the email forwarding.