You can list all domains that are parked on your server, sorted by the domains they are parked on top off. You can use this list to add mail configuration to the primary domain's CPanel, which adds the domain so the account can modify forwarders and default address for that domain. You can also use this list to unpark domains - refer to Unparking a domain for more information.
To list parked domains:
Click on the List Parked Domains link in the DNS Functions menu.
A list of parked domains is displayed, sorted by domain.
Click on the Add Mail Config to user's CPanel link to add mail configuration to the primary domain's CPanel, if required.