In the past two days I have moved a little more then a dozen mailboxs from Exchange 2003 to Exchange 2007. On 3 users Outlook 2007's it continues to ask for a username and password for the new server. The user then enters their info "DOMAIN\username" & "passord" that is exactly like their logon. Is Exchange on the new server not communicating with Active Directory properly? What might this issue be?