Symptoms
There is a notification configured for Service Deletion in the DUMMYGATE template: Home > Products > Service Templates > #ID DUMMYGATE service template, however the notification is not sent out on cancellation order placement and provisioning.
Cause
The notification will only be sent if the service is destroyed on cancellation (destroy on cancel set to yes). If destroy on cancel is set to No, then basically all is done is stopping the subscription, so if you need notification - assign it to Service Stopping.