There should just be a tick mark for a individual user that says "Notifications" and it enables or disables access to the notifications for that user.
We use NCentral for server and workstation monitoring and are now having the alerts sent to Service Desk. Our Email log is flooded with the bounce backs and rejections from admin@n-able.com. I know this address can be changed in NCentral, but I think the disabling of notifications at a individual user level is the better option.