This interface allows you to set up a default email address (catch-all address) for a domain. It will receive any mail for an invalid email address for the domain. You can also define how the default address handles incoming messages.
To view these settings, go to Default Address under the EMAIL section of your cPanel.
From here you can choose to change the default address settings for all the domains on your account. It gives you the option to discard all misrouted mail or forward all misrouted mail to a designated email address.