http://blogs.technet.com/b/samdrey/archive/2012/08/28/exchange-2010-public-folder-free-busy-folders-admin-accessibility-issues-troubleshooting-step.aspx  Using ADSIEDIT : go into configuration>services>microsoft exchange>administrative groups>... and navigate to any public folder database/store and check the properties Find a msExchOwningPFTree attribute: this should equal the distinguisheden-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)