Hello.
Thanks for adding more description. We'll becoming more clearer if you give more detailed description.
Here is your issue description is it correct ?
You have a AO rule in NAS probe for email notification.
If dirscan probe triggers threshold breaching situation alert, you are successfully notified via email.
If dirscan probe triggers threshold breaching situation resolved alert (we'd say clear alarm), you don't get notified via email.
Thanks
Yu Ishitani