Migrating Exchange 2003 (from an existing Exchange 2000/2003 Server) is a breeze – be sure you do it the easiest/sexiest way… This is how I do it…
1. Build your new Server into the same Exchange Organization
2. Service pack it, etc. Make sure its good, stable and being backed up before proceeding any further. Don’t forget stuff like Antispam, Antivirus (server, DB and gateway)
3. Modify your SMTP/settings so that this new server is the new SMTP Routing Bridgehead (will require firewall changes too)
4. ‘MOVE’ a couple of users to the new server making sure that mail gets delivered properly for them within the Exchange Organization and out of it (Internet). This is the sexy part as you will see that a user only needs to fire up Outlook and will get automagically redirected to their new Exchange Home Server (when you start Outlook, it tries to connect to your old Exchange Server – the server tells Outlook the user has moved and changes their Outlook profile to match)
5. Once that testing goes okay, before doing your final big move, you should take care of your Public Folders (I’m assuming here you want to decommission your old Exchange Server). Modify the public folder replication properties for all Public Folders homing them on the new Exchange Server
6. Modify your Exchange Recipient Update Services to use the new Exchange Server
7. Once all the above is done, start moving all the remaining users. Because this can happen seamlessly, do it over time. Schedule to move users when they are on lunch, etc. Or, do big mass moves at night – users shouldn’t be in their Outlook/OWA while moves are happening
8. Once all mailboxes are moved, double check that your Backups are running smooth… Reminder also that when you apply SP2 to the new Exchange Server, be sure to set the Maximum Exchange Server Database size beyond the new 18GB limit predefined (probably set to maximum 75GB)
9. Finally, once all users are moved, you will want to decommission this server. NOTE – if there are users away on vacation, they won’t do that one-time Outlook login to automatically modify their profile. This is no big deal as you would just need to very quickly visit their desktop and change the server they attempt to connect to. However, some folks like to leave the old server up a week or two to ensure they get as many people as possible automatically switched over (very transparent). For decommissioning – see the following article – http://support.microsoft.com/default.aspx?scid=kb;en-us;307917 – I’ve pretty much covered everything you will do but its good to do a once over before uninstalling Exchange on the first server (yes, I said uninstall – this is the cleanest way to get this server out of Active Directory/the Exchange Org.
Cheers,
Sean