I’m spending a lot on my email service every month. Would it be possible to stop sending emails completely (i.e. only send email verification emails whilst stopping all notification emails and summary emails) ? Coz users on my forum don’t really see it as a necessity.
P.S. I would like to suspend all email notifications and summary emails for all users (existing as well as new ones).
Hello
Change this site setting disable emails and in addition in admin > settings > user preferences find the emails and disable them as well.
I’ve done this. But will new users be sent a verification email when they join if I disable all emails?
AFAIK, that only disables notifications for posts/replies and summary emails. It should have no effect on invitation emails. If you have a test email address you can send an invitation email to make sure it does indeed go through. 
Alright thank you so much. Will do this!
They will not. I think what you want to do is change max emails per day per user to 1 and disable summary emails.