Exchange 2010, Multiple MAPI public folder trees were found, 2000/2003 pf-leftover

While opening the Public Folder Console on a Exchange 2010 you get following Error:

Error:

"Multiple MAPI public folder trees were found. It was running the command 'get-publicfolder -getchildren -identity '\' -server '[Exchange 2010 server name]'"

Cause/Customer scene:

This was in a 2^nd Exchange install environment with that customer. (2003 > Cloud > Back 2010 internal [2003 removed])

The customer had internal Exchange 2003 then swapped to some cloud solution and because they found out that the provider does read all their E-Mail and the "NSA" also they wanted to have it back internal away from the unstable cloud. Well not enough someone who does not understand public folder importance de-installed the Exchange 2003 and forgot the System Folder (He exported the PF with Outlook.exe and deleted the regular PF's) while de-installed the Exchange 2003 (Dead Objects where removed and he could Deinstall clean) but the PF-Structure was still there. Happened before and comes back with all Migrations.

Here is how it looks WRONG in ADSI:

This green is the object leftover from Exchange 2000/2003 which makes the problem.

Now before! You change anything in that direction without MPSS (Microsoft Support). You use NTBACKUP/Windows Backup to make a backup of the Domain Controller (No not your Netvault/Bexec/acronis/disk2vhd/netapp snapshot) AND you do a LDAP/LDIF export of the object you want to handle on a Domain Controller.

Here is how to export the OBJECT:

Get the DSN Name on the wrong Object > Right click and Properties:

Sample: "CN=Public Folders,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=customer,DC=local"

Replace that string with yours and run the command on a domain controller:

ldifde -f D:\edv\Falscher_PF_2003.ldf -d "CN=Public Folders,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=customer,DC=local" -p subtree

This will look like this:

Then after you check all you delete the Object:

After that reboot the Exchange and all should be fine