dmay,
I ditto Darrell. I have used MS support once. I was very impressed with this department. The call cost was $250, but they are skilled and professional techs.
Actually it was a free call. We use CA etrust and they released a bad AV definition that deleted a critical 2003 system file. This brought down servers that would not restart, no login possible. These servers are on Dell PE with RAID5, so I did not try Knoppix. Without access to the file system or logs, and needing to fix it ASAP, we where stuck. MS was already dealing with 1000s of calls for this issue, and once he told me, it was simple command line cab extractions to replace the files and command line to kill etrust services.
MS called back the following day and said since this was not our fault (CA is to blame) they where refunding the $250.00. I suspect MS billed CA or simply threatened them, but regardless, MS already had my money and they choose to give it back. I would not hesitate calling if you have googled until your keyboard is worn out. Maybe subscribe (fee based) to Expert-Exchange, I find this has good tips.
Regardless, you own Exchange 2003, why change this? I hate MS marketing and licensing. I don't plan on using Vista ever! I switched to OS X in December, never going back to MS on the desktop. Regardless, if you have the budget, Exchange and Active Directory are excellent products. Go visit scalix.com in your spare time......when 2003 is out of date, then migrate...just my 2 cents.
ryan