In cPanel, the catchall feature is referred to as "default address."
Enabling the default address allows all misrouted or misaddressed email to be sent to a particular email address rather than bouncing. Therefore, you should be careful when setting up a default address as this can increase your possibility of becoming a victim of spam or virus.
For security reasons, Online Ion will disables the catchall feature for all account types; however, it can be enabled upon request.