To turn message block on, from the home screen, tap Messages.
Tap the More icon.
Scroll to, and tap, Spam filter.
Tap the Spam filter toggle to turn Spam filter on/off.
Tap Add to spam numbers.
Tap the + icon to add a number to the message block list. Note: Adding a number to the "Block list" does not block calls from being received. For instructions on blocking calls view the Block calls tutorial.
Enter the Desired number in the Enter number field and tap SAVE.
To remove numbers from the Spam list, tap the Delete icon.