Hi Guys, We are having problems with an exchange 2k server, all services and exchange it's self seem fine, but users cannot authenticate (via Outlook, Outlook Express or OWA) on the server. The exchange server is a domain controller and we have two other DCs. Distribution lists, pointing to external email accounts and coming from external email accounts work fine. We had other instances of exchange 2k on our network (all Wink\2k servers) prior to this install. Any help/suggestions? Thoughts or ideas? Much appricated. Thanks.