mail gets disabled in our non prod all the time.. check your outbox and sent items and verify mail is flowing in that system.. if not enable it from teh email setttings <ensure you have an address for all mail to go to>

if mail is enabled and the event is firing... than the issue is in your notification

check the send to event creator and check the trigger for the email is pointing to the correct event... add yourself as a hard coded recipient and try it again