Steps to disable catch all / default email address in cPanel:
[1] Login to the cPanel of your domain.
[2] Click on 'Mail' icon.
[3] Click on 'Default Address'.
[4] Now click on 'Set Default Address' link.
[5] Enter :fail: in the text box and click on 'Change' button.
Note: If you set :blackhole: sender will not receive any bounce email but if you set :fail:, they will receive bounce email. Also :fail: is recommended option.
Regards,
Kailash
