I've been working a problem with MS support for 2 days now. Something they did last night is now preventing us from sending email to public folders. What they did was in adsiedit, under administrative groups, we have 2 orgs listed one is our old 2003 which has been removed for over a year and our current 2007 one. She deleted the folder hierarchies from the 2003 org, ran /preparead and then we had to manually edit the folder hierarchie in the 2007 org by adding the distinguished name of the Public Folder datbase to the CN=Public Folder under folder hierarchie. I've also noticed that when I go to PF admin tell the OAB to "Update Content" I get an error "MapiExceptionNoReplicaAvailable" hr=0x80004005. I'm waiting for MS support to call back, I've emailed them and made another call. Lets just say I'm not happy with the support I've been given.....

Well after pulling my hair out i decided to create a new public folder, mail-enable it and it works! THen i took an existing public folder, mail-disabled it, then re-enabled it and it works! So since we don't have too many public folders I just went through them all. Still NO CALL from ms, great support!