over http implementation in Exchange Server 2007 Outlook Anywhere, allows a much easier and fully automated client configuration, in case you are using Outlook 2007. In Outlook 2010 open the Account Settings for the Outlook profile that is configured. What is Outlook Anywhere? Now that Outlook 2010 has been configured for Exchange Server 2010 Outlook Anywhere, any time the user launches Outlook from a remote connection and can reach the perimeter firewall over the internet they will be able to securely access their mailbox as though they were. Make sure this external domain is pointed to corporate Exchange servers public IP address. The external host name you choose should ideally be one that is already included in the, exchange certificate configured on the Client Access server. . I think it's control-right-click on the outlook icon that lives in the system tray and it'll give you a couple additional options for testing connectivity - it might provide a little more info. Configure the Outlook clients to use Outlook Anywhere when connecting from remote networks.