Hi all, I have recently transitioned from Exchange 2003 to 2010 in co-existence phase. I'm not at the stage where Exchange 2003 can be decommissioned. All Mailboxes have been moved, Public Folders replicated and moved. OAB etc done. I have changed the RUS server in the Exchange 2003 console. I now plan to shutdown the Exchange server for 2 weeks to ensure there is nothng I have missed. Will shutting the server down cause any issues, with 2010. Will it try to contact it with the routing group that was setup automatically during setup? Is this the best method or would you just run-install. When I do come to un-install do I need to delete the mailstores and routing groups first? Thanks for your help Chris

While not specifically for Exchange 2010 the process is the same and will answer all of your questions :) http://www.msexchange.org/articles_tutorials/exchange-server-2007/migration-deployment/removing-last-exchange-2003-server-exchange-2007-part1.html One thing to note is that before you shut down the E2K3 server make sure you have set up your send and receive connectors on the E2k10 server so hat mail flow functions, also ensure that any port 25 firewall/NAT rules have been modified to point to the E2K10 server.Matt Cline - MCSE+M, MCITP: EA | EMA (2007, 2010) | Lync 2010 Blog: exchangeadventures.com

Personally I am not a fan of the shutdown and see what breaks method, because Exchange will expect the server to be there and some traffic will try and go to it. If you follow the guides correctly, then you shouldn't have any probelms simply because Exchange doesn't allow you to uninstall if the server is being used for any mailboxes or public folders. The Exchange 2007 version of the guide for removing the last legacy server is more detailed than the Exchange 2010 version and the process is the same: http://technet.microsoft.com/en-us/library/bb288905(v=exchg.80).aspx The only things you are likely to have missed are rarely used SMTP tasks - printer, scanners etc, which you would miss even if the server is off. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Hi Simon, Thanks for this. I have followed the guide and deleted the Mailbox Store on the old Exchange 2003 however when I try to un-install Exchange 2003 it comes up with an error message " The component Microsoft Exchange Messaging and Collaboration Services cannot be assigned the action Removal because: One or more users currently use a mailbox store on this server. These users must be moved to a mailbox store on a different server or be mail disabled before uninstalling this server. Any idea what these users could be, all users have been migrated to the new server some weeks ago and it allowed me to dismount and delete the private store. Thanks BTW, I have done a find in Active Directory to try and find the user that thinks its Exchange Home server but they are all showing as the new Exchange 2010 server.

There must be something triggering that message still on the system. In a few rare instances I have seen it happen when the system mailboxes are not set correctly - usually where there has been multiple databases and the database that holds the system mailbox wasn't the last database removed. Try this - recreate the mailbox database on the server and then restart the information store and system attendant services. That forces the system mailboxes to recreate. Then drop the mailbox database again. Finally attempt the removal of the server again. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.