Email notifications for updates received when it's turned off

Hi,
Thank you very much for great work!

I think this is quite big problem: my users reported me, that they receive email notifications when nodes updated, eventhough I have turned this option off by default, also checked it with my account and my personal option also was turned off.
The reason that is a big problem for me is that users started to sign out from watcher, because of a lot of my updates to nodes and thus a lot of email notifications they couldn't bear.

Can you please help me sort it out? Would be much greatful.

Cheers!
Mat