In case you do not want to block a telephone number anymore, you have to the delete the contact from the blacklist again.

1. Start the Avira Free Android Security App
2. Go to Blacklist
3. Click the “Options” key on your mobile phone and click Delete
   
   
    
4. Choose the contact you want to delete from the blacklist
   Please note: You can delete a specific contact or all contacts at once
   
   
    
5. Click Delete
   A small popup will appear to make sure, you want to delete the specific contact from the blacklist
   
   
    
6. Answer the question with Delete