Our Outlook Anywhere users are getting prompted for a user name and password every time they log in to Outlook. My understanding is that this is caused by using Basic authentication instead of NTLM. My question - If I change authentication to NTLM, do I have to touch any client machines or will Outlook pick up this change through Autodiscover or some other service? Is there anything I should do to verify clients will receive this new setting? This is on Exchange 2010 SP1 and Outlook 2010 SP1. Thanks