If you are receiving too many mails about invitation or reminder and you want to opt out of Facebook emails. Then you can follow following instruction.
If you have a Facebook account:
Go to settings and then go to notification setting.
Click Edit next to the notification types you want to receive and make sure the appropriate boxes are checked
You can also follow the unsubscribe link instructions located at the bottom of any email message from Facebook.
If you don’t have a Facebook account:
You can opt out of receiving emails from Facebook by clicking the link at the bottom of any invitation email. Doing so will put your email address on a “Do not Email” list.
After making the changes if you are still receiving Facebook emails. Then you can contact Social-tech-help Facebook support number, and our technician will help you with your problem.