Could you elaborate more on what those email notifications are about? This is because it seems that the 'Notify Watchers' checkbox only affects edits on Confluence pages.
However, the following changes will still notify the watchers, as mentioned in Watching Pages, Spaces and Blogs :
I suspect that it was one of these actions that triggered the notifications.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG