How do I see who I have getting notified of a registration submission.

How do I see who I have getting notified of a registration submission. I need myself; my executive director; and my event coordinator and at the moment only two of us are getting the notice. But I am no longer able to see them listed as I did. So not sure exactly where I need to go to included the other email address so all three of us are receiving.

This is a re-post of a comment on How to Delete Notifications/Autoresponder