I have an Exchange 5.5 server (SP3) installed on a PDC (WINNT 4.0 with SP6a). When I found that I couldnt change the user password by using outlook without windows logon to the Network domain, I installed and promoted another domain controller as my PDC and made my exchange server on BDC. Some of my users now can change their password, but some still cant. Anyone knows why?? Thanks for your help!!!