First and foremost:
My Exchange environment consists of both Server 2003 and Server 2008 clusters running Exchange 2007 SP2. All of my users log in using Smart Cards.
Some of my users are continually getting prompted for username and password when running Outlook 2007. The only users experiencing this are using Windows XP and have their mailbox hosted on one of my 2008 servers. When I move their mailbox to a 2003 server, they no longer get prompts for username/password.
I've called Microsoft, but they won't help because they no longer support Windows XP. Any help is appreciated. Thanks