Restrict Friends On Facebook
1. Login to Facebook and go to the Account drop-down menu at the top of any Facebook page and choose "Privacy Settings."
2. Select "View settings" in the "Fundamental Directory Details" section.
3. Modification the setting for "Send me messages." Your choices consist of Everybody, Friends and Pals of Friends.
Only emails from people that fall within the message personal privacy setting you choose will be delivered to your Facebook Messages. For instance, if you pick the "Buddies Only" setting, you will not receive messages from email addresses that are not verified to be one of your buddies. Instead, those senders will receive automated bounce-back replies.
Such articles Restrict Friends On Facebook thanks for visiting can hopefully help you out.