Can't expand public folders externally Outlook 2007 Client

I can expand Exchange 2007 Public Folders internally from a mailbox on 2013, but outside when doing the same procedure I get an error that I can't expand the Public Folders.

I'm trying to figure out right now if externally the usage of Public Folders is handled by the virtual directory /Public from the legacy servers.  To check I was trying to go to the legacy virtual directory and can't access it from the legacy url.  I only seem to be able to access the URL on the HUB itself.  http://localhost/public.

I wanted to look at my config for the Public folder virtual directory but for some reason can't think of the powershell command on how to configure it.  Ugh...