BLOCK: From the home screen, select the Messaging app. Select the Menu icon, then select Settings.
Select Message blocking, then select Blocked numbers. Note: To block unknown numbers, select the Block unknown number switch.
Select the Add icon > select the desired contact location > select the desired number you would like to block > select DONE. Note: To quickly block messages from a number that has called you, select and hold the number from your Call log then select Block number > BLOCK.
UNBLOCK: From the Blocked numbers screen, select the Trash icon. Select the desired number, then select REMOVE.
TURN BLOCK UNKNOWN NUBERS ON/OFF: From the Message blocking screen, select the Block unknown numberswitch.