Instructions

Block Messages
Go to "Settings" > "Privacy" > "Block & Filter"> "Block Messages".
You can set the message blocking rules on your own.
Keywords for Spams
Messages from unknown numbers containing particular keywords that you have set
will be recognized as spams.
Block Messages from All Unknown Numbers
All messages from unknown numbers that are not in your contact list will be blocked.
Blacklist
You will not receive any phone calls or messages from blacklisted numbers.
Add Blacklists
Go to "Settings"> "Privacy" > "Block & Filter" > "Blacklist".
You can enter numbers manually or select numbers from contacts.