I have recently migrated from Exchange 2007 to 2010. Everything seems to be fine but right after migration we noticed that none of Outlook 2003 clients can connect to 2010 server. I am suspecting problem with Public Folders as they were not on new 2010 server. I have created new Public Folder DB but it didn't fix my problem. Also when looking in ADSIEdit I came to know that I have two copies of CN=Public Folders (msExchPFTree). One is located in CN=Configuration,DC=..., CN=Services, CN=Microsoft Exchange and the other one is under CN=Configuration,DC=..., CN=Services, CN=Microsoft Exchange, CN=Organization Name, CN=Administrative Groups, CN=Exchange Administrative Group (FYxxxxxxx), CN=Folder Hierarchies. I believe that this is because I have two sets of Public Folders now (2007 and 2010). However Outlook 2003 still can't connect to Exchange 2010. Getting message: Your Exchange Server administrator has blocked the version of Outlook that you are using. Contact your administrator for assistance. Any help would be more than welcome as I have been looking at it for days now and still being nowhere. Thanks!

Out of the box, Exchange 2010 doesn't support Outlook 2003. You either have to enable encryption, or disable on the Exchange server. You cannot run Exchange 2010 without public folders unless you have exclusively Outlook 2007 or higher as clients. Have you replicated all of the content from Exchange 2007 to Exchange 2010? Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

I was trying to set up replication between 2007 and 2010 but no luck. I can't see PF in 2007 unless I put value 1 in msExchPFTree entry in ADSIEdit. The problem is that I have two of those entries. One for 2007 and one for 2010. If I put 1 in both I am getting messege in PF Console that there are multiple MAPI profiles. Thank you for you response! Do you have any other suggestions?

How exactly did you try to replicate the content across? All that you should have done is add a public folder database to the Exchange 2010 server, then use the AddReplicaToPFRecursive script which is in the Scripts directory. Then set the Public Folder database on the Mailbox database. The public Folder content will then replicate across. The Outlook issue is this: http://support.microsoft.com/kb/2006508 Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

I just ran the script which you have mentioned. How can I check if replication is happening? How it may take to replication to finish? My PF content is very small. Thanks!Kris

Compare the output of get-publicfolderstatistics between the servers. Public Folder replication is impossible to predict. Minutes to days is possible. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

How’s the issue currently? Public folder database related malfunction can cause the error “Your Exchange Server administrator has blocked the version of Outlook that you are using” You shouldn’t have two copies of “CN=Public Folders” entry in such scenario. The entry should only exist in the “CN=Folder Hierarchies” container Please backup AD at first for the safety, and then remove the one under the “CN=Microsoft Exchange” container Please check the “MSExchOwningPFTree” attribute on the public folder database via ADSI Editor, incorrect value will cause the same issue The correct value should be the “Distinguished Name” of “CN=Public Folders” entry in the ”CN=Folder Hierarchies” folder a. Start->Run->ADSIEdit.msc b. Expand “Configuration”->”CN= Configuration,DC=DomainName,DC=Com”->”CN=Services”->”CN=Microsoft Exchange”->”CN=OrgName”->”CN=Exchange Administrative Groups”->”CN=AdministrativeGroupName”->”CN=Folder Hierarchies” Please run ExBPA against the exchange servers for health check Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

The issue still persist. I have already deleted one entry - the one you have suggested, but it caused that I was not able to mount PF on Exchange 2007 and none of the 2003 clients was able to connected to 2007 as well. I had to recreate that object and everything went back to normal. Honestly I am a little bit puzzled as for now. Any help is more than welcome! I did run BPA but it didn't return any problems. Thank you!Kris

Issues seems to be resolved. I looked at your instructions again and manually changed value of msExchOwningPFTree to distinguished name from CN=Public Folders under Folder Hierarchies. Now after moving 5 mailboxes to Exchange 2010 they are able to connect after setting up encryption on client side. We will see how it works going forward. Thank you for your suggestion. I hope my problems with PF are finally resolved. Now I can slowly decommission Exchange 2007. Thanks again!Kris

Excellent!Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.