Hello, we using Outlook 2010 on Exchange 2010. Our company is changing email domain (ie from olddomain.com to newdomain.com) and I am trying to reconfigure Outlook accordingly. I go to [Control Panel > Mail > ... > Exchange Account Settings] and I change the username from email@example.com to firstname.lastname@example.org. Everything seems nice & dandy. However in the background the associated username remains @olddomain.com (I can see that in the popup window with the credentials and I also confirm it through the autodiscover mechanism). Any ideas why this is? Is there a way to completely change the olddomain to newdomain in the Oulook config? Thanks!