Disable default Email address in cPanel

If you handle a domain,earlier or later you are limited to get e-mail at your domain for an address that does not available. Most of time this e-mail comes from spammers, wondering that “abc123@domainname.com” might be a practical current e-mail address at your domain. It might also come from someone mistyping the first aspect of your genuine e-mail address.
The default email address will always are available on cPanel at this time, but you can modify the behaviour for the default email address to not have e-mails go to it straight on account creation.
Option-1 you can do it in WHM > Tweak Settings > Initial default/catch-all forwarder destination area.
Default Email
You could change it to “Fail” rather than the “System account default” selection, then click the “Save” button there.
Option-2 cPanel manages this e-mail through the Default Address page.
Default Email2
This Default Address Maintenance page gives us all the options to handle non-routable incoming mail to your domain.
Discard with error to sender:
This is the standard option. Any email sent to a non-existent email address is bounced back to the sender with a message. Since this informs the sender that the message was not delivered.
Forward to email address:
This option forwards these types of emails to another e-mail address of your choice. You will have to check this address every so often to make sure that you are not missing email.
Forward to your system account:
This option sends unrouteable email to the cPanel user’s default e-mail account. This address has the same username as the cPanel account.
The benefit to sending email to this address is that any genuine e-mail that may have been sent to a mistyped address is stored in this account. The disadvantage is that if it is not checked often, the account could fill with junk and run up against the domain’s email or disk space quotas.
Pipe to a program:
This choice directs unrouteable email to a program of your choice. This gives you a lot of flexibility: you can do to this kind of email whatever can be programmed.
Discard:
This option discards unrouteable email without informing the sender or you directly. The benefit to this is that no junk ever strikes the server, AND the spammer gets no verification one way or another that email is being sent to the address. The disadvantage is that it is likely that genuine e-mail would be removed without caution if the sender uses the incorrect e-mail address. Because of this possibility, cPanel alerts that this option is “not recommended”
Hopefully this brief article will help you to determine the best way to handle unrouteable mail to your domain.
I also did a post recently to clear default email account that can also be helpful.