Exchange 2003 SP2 on 2008 R2 domain? Not so fast

January 3, 2010 · 21 comments

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Windows Server 2008 R2 LogoThere has been a lot of discussion about running Exchange 2003 SP2 on a Windows 2003 server while upgrading the domain to Windows 2008 R2 native mode. There are two real authorities that I rely upon and unfortunately there is disagreement.

First is Microsoft TechNet. According to their Exchange Server Supportability Matrix, last updated on 12-09-2009, it clearly shows that the Windows Server 2008 Forest Functional Level is not supported for Exchange 2003 Sp2.

Second is the Microsoft Exchange Team Blog. According to an entry from 11/30/2009, they made several updates to the supportability matrix which includes support for writable Windows 2008 R2 Active Directory Servers. This news was widely applauded by customers, including myself.

So, I made the decision to upgrade my domain from Windows 2003 SP2 to Windows 2008 R2. So, I installed a new server, joined it to the domain and promoted it to a domain controller. I moved all of the functional roles to the new server and then demoted my Windows 2003 server to a member server. Next, I upgraded the functional level of the domain to 2008 R2 and waited for the fireworks or the calm…

Well, everything behaved quite normally. User accounts did not act any differently on XP, Vista or Windows 7. Users continued to function without noticing any real differences. I was prepared to claim victory and give the nod to the information from the Microsoft Exchange Team.

That is, until a new user needed to be added to my domain and given a mailbox.  As usual, I went to my mail server and used the AD Users and Computers utility to add the user.  I created everything, including the mailbox and waited for everything to sync.  It never did.  This is a very small network and things take just a few minutes to execute.  I waited for over two hours and still no mailbox.  I tried different variations and ways to make this work, but nothing would or could create a mailbox on the Exchange server.  Just to keep things running, I had a few test accounts set up from earlier, so I deleted one of those accounts and re-associated its mailbox with my new user.  That worked and kept my environment operational.  I commented on the Microsoft Exchange Team Blog article, but have not received any responses.  There are no items in any of the event logs or other indications on either server to diagnose what went wrong or where the error occurred or what the error was.  Just silence.

I found a similar article where another used had the same problem, but I am unable to find that URL for reference.  If you’ve had a similar problem or have other references to this issue, please pass them along.

For now, I still have a working environment and my old Windows 2003 domain controller has been completely decommissioned and turned off.  I am moving onward and upward in my quest to be on the latest Microsoft technology.  So, my next venture will be to install Microsoft Exchange 2010 on a Windows 2008 R2 server and pull out my old Exchange 2003 server.  Wish me luck.

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Article by Steve Van Domelen

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  • Strausy

    Seems as though the TechNet article has been revised to include support for 2008 R2 Domain Controllers with Exchange 2003 SP2.

  • dbryan

    This is exactly what I plan to do, I have the same setup.
    please keep us updated!

  • RobD

    Hi, Any new info on this? Is it safe to go to R2 Functional Level while still having Exch2003 env.? I read that Ms supports it – but does it work?

    • Rob,
      I have done some testing and others that have read this article have also tested their environments and we all seem to agree that you cannot raise the functional level of the domain to 2008 R2 and have the ability to add users to Exchange 2003. We do not know about any other limitations, but that one seems certain.

      Our testing also shows that you can upgrade your domain controllers to 2008 R2 and have a functional Exchange 2003 environment as long as the domain stays at the 2003 functional level. You must upgrade to 2010 Exchange server before upgrading the functional level of the domain to 2008 R2 based on our experiences.

      • Daniel Bryan

        So after my research I have concluded that you can run exchange 2003 SP2 on an 2008 domain running in 2008 domain and forest functional level, you will have to manage your mailboxes from the exchange server using the adminpak and/or exchange management tools.
        Correct? I mean does anyone know for sure you can add a new mailbox this way?

  • I have upgraded the schema of our 2003 AD and added the first 2008 R2 DC a few months ago and have now done some additional testing for upgrading the remaining 2003 DCs to 2008 R2 as well. We are also running an Exchange 2003 environment and I have read that there might be problems with creating mailboxes after introducing 2008 R2 to the Active Directory. Here's what I found out:

    1. The schema upgrade to 2008 R2 (schema version 47) went very well and caused no issues with Exchange.

    2. In my latest tests (performed in a testing environment) I transfered the FSMO roles from a 2003 DC to an existing 2008 R2 DC. I then demoted the old 2003 DC, installed a new 2008 R2 server with the same name and IP address of the old one and promoted it to a DC again. At this time there were no 2003 DCs left. Both DCs were running 2008 R2 with however domain and forest functional levels still set to 2003.

    For testing purposes (as I read from the issue described in this article before) I connected to the Exchange server and tried to create a new user with mailbox. And what happend? The mailbox was not created and the Exchange tabs in the user's settings were not updated with Exchange settings (no mail address etc) eiter. While trying to add the user's name in Outlook I received a message stating that this user is not available in the address list.

    After some further searching on the web I remembered that I changed some RUS settings during my tests. What I have done and what caused the mailbox not to be created was the following: By default, there are two RUS available in Exchange. One Receipient Update Service for the Enterprise configuration and one for each domain. During my tests I only saw that both were pointing to the same domain controller so I just deleted the RUS for the domain. Unfortunately I didn't remember that both RUS are required…

    After creating the domain RUS again the mailboxes of the new users were created immediately!

    Hence I really would check the RUS in Exchange. Even if you haven't changed anything by yourself – maybe deleting and re-creating the domain RUS will help.

    After everything in the testing environment turned out to be working fine I also raised the domain and forst functional levels from 2003 to 2008 R2: No problems at all – mailboxes are still created fine.

    Upgrading the production environment is planned for mid-June.


    • RobD

      Thanks for that info!
      So there might be a solution after all. Both my RUS are pointing to one of the new DCs. I changed that manually prior to removing the last 2003 DC some time ago.
      But do i have to re-create them or is it enough to just change the Domain Controller setting in them?

      Br /robert

      • Yeah, and when I performed the RUS changes prior to removing the 2003 DC I just deleted the domain RUS 🙂

        If you don't have any DCs that are going to be removed I don't think you need to change anything!

        Question to the author of this blog: Have you still been able to create mailboxes after you migrated all the DCs to 2008 R2? Or haven't you created any mailboxes prior raising all functional levels to 2008 R2?

        • I upgraded the domain and the functional level before attempting any Exchange operations. Matter of fact, it did not occur to me to test that until it was too late. Thanks for your comments and extended testing. I have another production environment to upgrade and I will follow your suggestions.

          • Even though in my case removing the domain RUS was my own fault it can also be caused by a scenario like this:

            – DC01 with 2003 is the only domain controller and therefore the only one used for RUS by Exchange

            – As 2003 cannot be upgraded inplace to 2008 R2, a second domain controller with 2008 R2 (DC02) is added to the domain

            – The FSMO roles from the old 2003 DC are transfered to the new 2008 R2 domain controller.

            If DC01 is demoted in this scenario, we are likely to experience the known problems. Since DC01 was the only DC, there is no other RUS specified in Exchange that can handle the creation of mailboxes etc.

            Since you wrote in your article that you indeed demoted the old server I think the issue really was caused by an obsolete RUS entry linking to the old DC (unless you have renamed the new DC to the old name or there were additional DCs configured with RUS, which would be interesting to know).

            • You are correct. I demoted the old server and the new domain controller has a new (never used in the domain) system name. This was a small environment with only a single DC. Your scenario matches what I did, so your solution looks like a winner.

  • Pingback: Probleme mit Exchange 2003 nach Migration auf Windows Server 2008 R2 Active Directory? « layer9.()

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  • Juan Machado

    2 days trying to figure out what the problem was after promoting our
    domain from 2008 Functional level to 2008R2. Every 24 hours the Exchange
    services didn’t start with ” Topology” errors. Only thing to fix it
    was to run Exchange 2003 SP2 command ” update /DomainPrep ”

    24 hours later, same problem. Exchange broken.

    Exchange Domain Servers was missing from that group policy. Not sure
    if the promotion to 2008R2 deleted that, or if it was not necessary for
    Exchange 2003 SP2 to live in a Windows 2008 domain…

    Computer Configuration
    Windows Settings
    Security Settings
    +Local Policies
    User Rights Assignment
    Manage auditing and security log

    – Juan Machado

  • Paul Vanwijck

    i always recommend to run ExBpa first; the problem of a malfunctioning RUS would be detected.

  • WallaceTech

    Guys. I am so glad i found this article. What is the latest on this? I have all my DC’s at 2008 R2 and my fuctional level at 1003 native mode. We are running Exchange 2003 Sp2

    Is this now safe to update to 2008 Native mode or is Exchange 2010 the jump then do it?

    • If you follow the thread from Michael, you can see it is possible. However, if you can upgrade to Exchange 2010, I would do that first and then upgrade the domain. It will be much cleaner and easier to do it that way in my opinion.

  • Zohar

    Thanks, this blog and the comments really saved my neck. As long you keep the domain level at 2003 there will be no problem with exchange 2003. You must point the RUS to the new domain controller and rebuils both of the RUS.
    Thanks Guys

  • JohnKohos

    You didn’t mention whether you installed Exchange 2003 on a Windows 2008 server. That’s the real question I’m chasing.

  • Jim

    I want to run adprep on my 2003 domain to prepare for adding a 2008 DC but have no plans right now to make it a native 2008 domain. I’m guessing my Exch 2003 config on a 2003 server will still function fine. Thoughts?

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