To turn message block on, from the home screen, tap Messages.
Tap the More icon.
Tap Spam filter.
Tap Add to spam numbers.
Tap the Add icon to add the entered number to the message block list, and enter the Desired number in the Phone number field. 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.
To remove numbers from the Spam list, tap the Delete icon.
Selected Desired numbers.
Tap the Delete icon.
Tap OK. Note: To turn off spam messages off, tap Messaging > Menu icon > Settings > Spam Filter > ON/OFF toggle.