We had already seen how to block users by email in Facebook but the steps discussed earlier has changed with the recent update to Facebook. Now if you want to block people by email or name in Facebook, click the drop down arrow available at top right corner and select Privacy Settings from the drop down list.
In the Privacy Settings page, navigate to Blocked People and Apps and click the Manage Blocking link.
In the Choose your Privacy Settings page, navigate Block users section. To block a user, enter person name or email and click the Block button.
Unblock users in Facebook
Facebook users can unblock a user using the Manage Blocking option. A blocked user will appear under the Block users section as show below.
Clicking the remove link appearing next to the person’s email address should unblock the user.