Frequently, emails sent to an email account that has not been created or does not exist on your domain will be taken to the default email account in cPanel, and it is likely that these emails will end up saturating the space of your hosting account.
How to disable the default email account?
You can configure the status of the default email account by clicking on the “Default Address” icon in the “Email” menu of the Cpanel control panel.
Click on the “Download with error to sender (in SMTP dialog)” option in the “Maintain Default Address” box.
There you will also have the possibility of indicating the error message that will reach the sender. By default the error message used is "No Such User Here". It is recommended to use that error message, which is the one used globally for this type of errors.
Finally click on the “Change” button.
This way, mail will no longer reach the default email account of your hosting account.
How do I delete the emails that are already in the default account?
By logging into your cPanel, you can access the default email account via webmail by clicking on the webmail link that appears on the right side. The password for the default account is the same as that used to enter your cPanel control panel. Using the Roundcube or Squirrelmail email clients you can delete them en masse.
If there are many emails in the default account, perhaps it is best to use an FTP program. When entering via FTP, it locates the /mail directory, and exactly within the /mail directory there are two subdirectories: one is /cur and the other is /new. You can delete the contents of these two folders and you will effectively delete all existing email in the default account.
Important: Make sure you delete the contents of those two folders, not the folders themselves. If there is a lot of mail that is there, it may take some time to be deleted. Don't delete anything else inside /mail, as it corresponds to other real email accounts on your domain.
