Hello,

I think it is normal, but you can edit this settings, at the top of the page click on your nick name and click on view profile, at left in your profile click on Edit Setting, in this area you can edit the notifications.

Or in the emails that you received, at the bottom, maybe there is a link to stop the notifications!

Does the email you received have an unsubscribe or opt-out link? I can't find the right page just browsing around this site.