What must the restore destination be for a Public Folder?
The restore destination of a public folder must be the same folder tree (All Public Folders) and must exist on the destination Exchange Server.
How do I restore a deleted Public Folder from a user's mailbox?
In situations where a Public Folder created in a user’s mailbox (not the Administrator’s mailbox) is backed up and then deleted before it is restored, the user will not see the folder after the restore because of a change in ownership. For security reasons, the system assigns the ownership of the restored folder to the Administrator. Therefore, the user will not see the restored folder unless the Administrator changes the permission back to the user. The Event Viewer will issue the following message to notify you of this condition:
"Warning: Please manually set folder [...] permission."
If you want the user to be able to view that folder after the restore, which would normally be the case, then the Administrator must manually set the folder permission back to the ownership of the user.