Exchange 2010 and InterOrg (IORepl)
Important Update
Exhange 2010 SP1 supports InterOrg, but it’s important to stress that although Exchange 2010 SP1 includes support for the InterOrg tool, you need to do the following to get it working:
- Use a 32-bit based Windows 2003/R2 Server
- Install the Exchange 2003 System Manager on the machine running InterOrg
- If enabled, disable the RPC encryption requirement on the CAS server used by InterOrg
- One of the InterOrg endpoints need to be an Exchange 2003 server (no direct Exchange 2010 < > Exchange 2007 replication)
The old InterOrg (IORepl) tool doesn’t work directly against Exchange 2010. Well, here’s the deal. You will be able to configure the tool and get public folder data to replicate, but free/busy info will not.
This is important to bear in mind if you think you at some point in time need to provide free/busy sharing between Exchange 2010 and Exchange 2003 (or earlier) orgs. In that case, you need to point InterOrg at a legacy server (Exchange 2007 or 2003) located in the Exchange 2010 organization.
So I guess we have one more reason to introduce an Exchange 2007 server before we deploy the first Exchange 2010 server in a new Exchange 2010 org. Or keep a legacy server around if you’re doing an upgrade (formerly known as a transition) from Exchange 2003 or 2007 to Exchange 2010.
Will this issue be fixed? Well time will tell. There is a bug opened for this, but we all now the Exchange Product Group is busy with Exchange 2010 SP1 and many other things 
Thanks to Nino Bilic for this tip.
Jeremy Says:
December 3rd, 2009 at 11:10 am
I’m glad to see your post. I have been fighting this for about a week. So the problem here is that I know have a native 2010 exchange org, and cannot install a legacy 2007 mailbox server. So the only solution at this point is to rip out the 2010 install and go back to 2007 so we can replicate the public folders and Free/Busy? This doesn’t seem to be a viable option for companies wanting to migrate directly to 2010. I’d love to see a fix or work around for this soon.
Henrik Walther Says:
December 3rd, 2009 at 1:21 pm
Not ideal but a legacy server is the only solution to this issue right now.
If it will ever come, we shouldn’t expect a fix in the near future.
Joining the Digital Content Exchange | Cheap Technology Buys Says:
December 17th, 2009 at 6:55 pm
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Kyle Says:
February 24th, 2010 at 11:55 am
Do you have any more details on this bug? Is there an official Microsoft article?
Henrik Walther Says:
February 24th, 2010 at 12:14 pm
Unfortunately nothing public yet.
Andrew Says:
March 1st, 2010 at 7:32 am
I can get the data replicating to the e2k10 server if i create a public folder on the e2k10 with the correct permissions. If I select to replicate all sub public folders from a exchange 2003 server this data is not replicated and the sub public folders are not created automatically. Is this part of the bug ?
Anyone got this working for e2k10 yet ?
Thanks
Henrik Walther Says:
March 2nd, 2010 at 6:45 am
Tests have shown one of the issues is exactly what you describe (problems replicating sub PFs).
Andrew Says:
March 3rd, 2010 at 9:55 am
thanks for that, it was driving me mad trying to fix it.
Darren Says:
April 6th, 2010 at 6:56 pm
Has anyone successfully replicated PFs, free and busy times across trusted forests?
Henrik Walther Says:
April 6th, 2010 at 11:40 pm
Yes.
V Says:
October 19th, 2010 at 9:19 am
Hi,
Will in your article you mention that IOrepl will work if your Exchange 2010 organization has a 2003 Exchange server.
Your article says that this will work if you are using Exchange 2010 SP1. But will this work if we are using Exchange 2010 RTM.
So one side Exchange 2003 and the 2nd side is Exchange 2010 RTM in the 2nd side there is a 2003 Exchange 2003 server that is replicating public folders with exchange 2010.
Thanks,
V
Henrik Walther Says:
October 20th, 2010 at 5:17 am
So here’s a situation where we’re caught in the middle of what works and whats supported.
To answer your question then yes it works with Exchange 2010 RTM org (with Exchange 2003 server as endpoint for InterOrg) and Exchange 2003.
Henrik
V. Sujith Nair Says:
July 1st, 2011 at 6:02 pm
Hi Henrik,
I am attempting to set up cross forest free/busy.
Both the Forests have Exchange 2003 and Exchange 2010 servers.
I need to set up IORepl to replicate Free/busy information between the two forests.
Is this supported as far as I have both organizations having Exchange 2003?
If this is supported then I would, after replicating the free\busy between the two forests, have to set the availability address space as Public folder for the other domain i.e for ForestA availability address space in ForestB as Public Folder and vice versa.
Cross forest availability using Availability Service could be set for free\busy access between the two Exchange 2010 but in this case when a user from source forest Exchange 2010 would attempt to access the free\busy information for the user in Exchange 2003 in the remote forest it would not work right?
I just wanted to confirm if my understanding of Availability Service is correct.
Thanks,
V. Sujith Nair.