Hi Monya,

have a look on this sites:

"How to recover deleted public folders or items that are deleted from public
folders by using the PFDAVAdmin tool in Exchange 2000 Server or in Exchange
Server 2003"
http://support.microsoft.com/kb/924044/en-us

"The PFDavAdmin Tool"
http://hellomate.typepad.com/exchange/2003/10/the_pfdavadmin_.html

On this site:
http://email.ku.edu/faqs/publicfolders.shtml

I found this information:

"Items stored in individual Public Folders can only be restored within 72
hours of being deleted. After that time there is no way to recover these
items."

- Select the public folder from which the item was deleted.
- On the Tools menu in the Outlook client, click Recover Deleted Items.

More information:
"How to recover deleted items in Outlook"
http://www.intermedia.net/support/kb/default.asp?id=728

Maybe it helps.

--
Oliver Vukovics
Share your Outlook PST files without Exchange: Public ShareFolder
Synchronisation for Outlook and Exchange: Public SyncTool
http://www.publicshareware.com