BLOCK: From the home screen, select the Messaging app. Select the Menu icon, then select Settings.
Select Message blocking, then select Blocked numbers.
Select the Add icon > desired contact location > enter the desired number > select BLOCK. 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 list, select the Delete icon. Select the desired number, then select REMOVE. Note: Select REMOVE again to confirm.
TURN ON/OFF BLOCK UNKNOWN NUMBERS: From the Message blocking screen, select the Block unknown numberswitch.