Hi, I just recently exmeged all my exchange 5.5 mail accounts,shutdown and removed my exchange 5.5 server, then installed exchange 2003 in a new administrative site. Then I mail enabled all the the users that have pst files and exmerged the pst files back into exchange 2003. Created a dns alias from the old server to the new one. My problems is that outlook 2003 clients that have the old exchange5.5 profile cannot connect to the exchange 2003 server (even with a dns alias). Is there a registry hack/modification to change the old settings to the new server? thx jason