Many people have a problem regarding this issue, getting too many notifications, unwanted emails to your Email Inbox.If you are an active user of facebook, your Email inbox may get filled with hundreds of Notification Emails daily. So if you want to filter your Email-Notifications Settings, then Click Here.
Then you will be able to see Notification settings as I shown in this below picture,

How to stop unwanted Facebook Notification Emails to your Email Inbox ? ? - New

Now choose your Email box settings as per your choice,
If you want Email Notifications about photos you’re tagged in, messages you’ve received, friend`s comments and more, then choose the 2nd Option – Important notifications about you or activity you’ve missed.

If you want Required-Useful-Limited Email Notifications about your Facebook Account Login, Security and more important information, then choose the 3rd Option – Only notifications about your account, security and privacy.

I personally suggest everyone to choose the 3rd option because its the best feature for a limited Important Email Notifications.

Note: If you are getting emails from a ‘Group’, visit the group and look at the upper right side of that group.
click – Edit Settings and un-tick the email notification box.