Using NodeBB as mailgroup

[Chong]

I'm starting using NodeBB. It works great till so far.
The most important functionality of my site is email notification. The only way I know to do this is asking everyone to watch a thread. But this is not straight forward.
What I want is some utilities that can send emails to all the users in a group. Is it possible with current version?

P.S. I think notification to all users when new post in a certain category suffices.