if a mailbox is being shared between multiple users and for some reason not all folders are visible to all the users. First thing you might want to do is to consider resetting the permissions of the mailbox.
The tool you would use for this purpose is PFDAVAdmin.
- Instead of connecting to public folder on a given exchange server, connect to all mailboxes of the server where the concerned mailbox is.
- Right click the mailbox name and select Propagate folder ACEs
- Check “NT AUTHORITY\ANONYMOUS LOGON” and click on OK
even though the level of permission is none “Anonymous Logon” has to be listed in the ACL in order for the folder to be visible to everyone who has permission to the mailbox.