Yes, there must be an option for admins to set instant email notifications setting on a new reply to a watched thread like in xenforo and vbulletin for new members and existing members. Mybb's notification system is not that powerful and don't have such option yet.
Scroll to the bottom of this thread, click "Subscribe to this thread", then click "Instant Email Notification". It's already a feature.
Also there must be seprate options to set webmaster email and contact email.
Yes thats a feature but i am talking about automated notifications that admin will set from acp for new users, is it already available?