After a migration from Exchange Server 2007 to Exchange Server 2010 I encountered a problem with the replication of public folders. It seems they would not replicate regardless of what I attempted.  I spent sometime looking into this, and not wanting to HACK in a solution just to make it work.  I wanted it to work and work right. I am here now to share some simple steps to look into if you a similar issues with public folder replication.

History: The public folders in this origination was from a Exchange 2003, migrated to 2007 (issues along the way) and not being moved to Exchange 2010.

From what I have read that this is a know issue and seems to happen with Exchange organizations that have previously run versions of Exchange Server 2003 or below.

The Exchange Server 2010 Application Event Log will have this error:

The store driver couldn’t deliver the public folder replication message ” ” because the following error occurred: The Active Directory user wasn’t found. This is Application Event ID 1020

The cause of this error:
A legacy container in Active Directory for the Exchange 2003 (or earlier) in server objects.

Do not follow these steps if you still have Exchange 2003 or earlier versions running in your organization.

Launch ADSIEdit.msc and navigate to CN=Configuration <your domain>, CN=Services, CN=Microsoft Exchange, CN=<your org name>, CN=Administrative Groups, CN=<your legacy administrative group>, CN=Servers.

If you no longer operate any Exchange 2003 or earlier servers and the Servers container is empty then you can delete the container.

I was able to replicate the public folder hierarchy and content from Exchange Server 2007 to 2010 after doing this.  How awesome is that!

– Jermal