I have deployed an additional Exchange 2003 (sp2) server in my organisation to replace our currrent exchange server. I am slowly moving mailbox's from the old to the new exchange server. Today, i have had users who are now residing on the new exchange server, being prompted to authenticate to the old server. Why is this, and how can i stop it? Also, what should i watch out for when decomissioning the old exchange server?Cheers.

Hi, I would like to know whether the user use Outlook logon his mailbox. If the user use Outlook to access his mailbox, please check whether his Outlook Profile is still set to connect the old Exchange Server. If the Outlook Profile is still set to the old Exchange Server. I think that it is normal the Outlook needs to connect to the old server firstly. Then, the Outlook will correct its profile setting and connect to the new Exchange Server. Regarding your second question, I suggest that you can keep the old exchange server offline several weeks. If nobody complains the issue. I think the old exchange server can be decommissioned. Mike

1 - The users outlook has detected the change in servers, and now points to the new server, and it still asks for authentication from the old server. 2 - I dont think keeping the server off for a few weeks will do the trick. Im actually looking for advice from someone who actually knows the process , not just a guess. Something like this guide actually - http://www.msexchange.org/tutorials/Removing-First-Exchange-2003-Server-Part1.html There are processes and procedures we need to stick to here!!!!

Did you move the public folder replicas to the new server? If not the users may be trying to go back to the older server for Free/Busy, OAB, etc. Exchange SP2 added an option to move all replicas.. Right Click the PF store on the old server and choose "Move all Replicas" This can take some time to replicate. Also be sure the RUS is pointing to a server other than the one you are replacing.. Check the address books and recipient policys for legacy DN's that point to the old server. Check SMTP and site connectors to be sure none are using the old server as a bridgehead or smarthost. When you are sure it's all cleaned up then shut down all exchange services for 1 week..(or the entire box if allit does is exchange) If nothing breaks uninstall exchange.. If you missed anything major it will tell youbefore startingthe uninstall process and quit. Some snags outside exchange I've encountered is applications and unix systems using that server for a mail relay.. Other services on the server like WINS, DNS and even DHCP one time.. One site had tweaked the Exchange mailbox server to also be theOWA box. The truly ugly ones are Exchange on DC's.. as a rule I always rebuild a DC that has had exchange removed from it.