Deny folder structures in Public Folders

Hi everyone

I am creating email accounts for clients outside of our domain and therefore would like to block the GAL, PFs, and folders in the PFs.

I've been successful blocking the GAL and PFs through ADSIEdit on my domain controller but these users are still able to see and access email templates that we use internally that are located in a folder in PFs, I am not sure why denying access to PFs hasn't blocked this.

As a test I also blocked this security group from the Folder Hierarchies in ADIEdit but that doesn't seem to fix the problem.

Is there somewhere else or some way to deny this permission?  It is the last piece of my puzzle.

Thanks!