How to Unblock Facebook From Sending Messages
Facebook notifications, or updates, keep you apprised of certain actions related to your account. The social networking site will send you a message when another user initiations a communication or action with you, such as commenting on one of your posts or asks to list you as a family member. If the notifications become a nuisance, blocking them takes just a few seconds. Likewise, unblocking messages is easily accomplished with just a few clicks of the mouse.
Click on the "Account" link in the top right corner of your Facebook. Choose "Account Settings" from the menu.
Click the "Notifications" tab.
Enable email notifications for a particular Facebook action by clicking the box next to it in the "Email" column. Some actions, including "Posts on your wall" and "Tags you in a photo," also have an SMS column. Check the box in that column to receive text message updates for those actions.
Scroll down to the bottom of the page, and click "Save Changes."