If you go to your account settings on Facebook from the drop down arrow beside the lock icon, you will be brought to a page where you can edit your notification settings.
From here, on the left of the page, you will see the Notifications tab, and from there you can edit your Email notifications.
Once you click through to edit the Email notifications, please be sure that your settings match the ones listed below:
“ONLY NOTIFICATIONS ABOUT YOUR ACCOUNT, SECURITY AND PRIVACY”
Once this is selected, you will no longer receive email notifications from Facebook.