To my understanding, all users of the server has the option to enable and disable Server Notifications.(listed under Emails).
Example: Workflow added to collection, Workflow Updated in collection.
To enable a particular notification, EACH USER has to add a particular notification to a Email Group.
Then, enable the Email Group.
Requirement: Change email notification sent to only to one email address for a particular notification(Example: Curator created a new active user account).
All users who have activated this notification should not receive it.
Thank you.