You can allow external web servers to access your MySQL databases by adding their domain name to the list of hosts that are able to access databases on your web site. localhost stands for the server that your site is currently on.
1 To access
the MySQL Account Maintenance Menu, click
on the
icon
above the words MySQL Databases
on the main screen of your cPanel interface.
2 Type the name of the server into the blank field next to Host: (It should be in the following format: test.cpdocs.net, server1.cpdocs.com, ns1.cpdocs.com, etc).
3 Click on Add Host to allows that server to access your MySQL databases.
To add a group of servers, you can use %.domain.com which would include all of the following: ns1.domain.com, server1.domain.com, test.domain.com, etc.