Hide CrossBox in webmail for some users

Question

We'd like to offer CrossBox just with the more expensive plans. Is it possible to hide CrossBox from webmail options for everyone else? 

Is it possible that we can disable some users or an entire reseller on cPanel/WHM to set CrossBox as their Webmail Application when accessing cPanel's Webmail? 

Answer

You can use the WHM's feature manager to control which packages have access to CrossBox.

Even though CrossBox will appear as a webmail option in cPanel for all users, only users and resellers that have it enabled in the WHM's feature list will be able to use it/log in.

cPanel currently does not provide a way to programmatically control whether the webmail app visually shows as an option in the webmail interface.