I also wondered, yet I couldn't find any settings to this regard in the Preferences... Only getting e-mail notifications for topics I started.

Same here...
It appears that I still receive emails for answers marked "Best Answer", regardless of whose answer it is.

I think this is a big problem!

I see e-mail notifications have been disabled in the forum settings.
I think this is because Zoho recently allowed people to send an automated e-mail to everybody by a simple click of a button ("hey, see my question!") and it annoyed lot of people. I don't know if they fixed that, so I don't know if I can restore the notification setting.

That makes sense.  Is there a place where one can view "all followed posts"  that would do the trick form, as i can just check in and see if there are new replies.  I'll look around and see what I can find.

I found back the related thread: How to stop receiving emails?
Do you still see a "Notify all the members" when creating a topic? The opened issue isn't closed yet.
If the button is gone, perhaps I can restore the notifications.

I don't see that option anymore so maybe we're safe?  

OK, I chose to switch the notifications to Enabled again, hoping it will annoy nobody!