Why is every user able to view and subscribe to all users folders under cPanel's install of Squirrelmail?

Does anyone know how to fix this? I've scratched my head over the config.php file for hours and cannot figure it out.

Any help is appreciated.

R U sure that any user can subscribe to all users folders ?

It should only be the main account of the domain who can subscribe to other accounts (only the pop accounts of his domain)

Yes -- within a domain, any user, and the main account holder has access to all folders within that domain -- that's no good. I am running the latest release of cPanel.

I cannot figure out why this would be. Surely cPanel should not let anyone view anything but their own folders?

By default the main account should be able to see the other folders but the pop users can not see each other folders. That's how it goes in Horde too. If pop users can see other users folders you should contact cpanel.