I am using Outlook with an Exchange Server 2007 from outside a company network. The address to this Exchange server is given as https://externally-reachable-address/EWS/Exchange.asmx . However, when I VPN in, apparently the Exchange server overrides this to be https://internally-only-reachable-address/EWS/Exchange.asmx and remembers the new address. When I stop the VPN connection, obviously the internal address is not reachable, so I will not get any email and scarcely a warning about this until I think to dive into the account settings and correct the address to point to the externally reachable address again manually.

For a number of reasons, staying connected with the VPN every second I want to use Outlook is neither preferable nor viable. How do I tell Outlook to disregard the change telegraphed by the server and keep using the address I entered manually?

(I know that manually remapping the internal server name to alias the external server name in e.g. the hosts file is a technical workaround - one that will create other issues instead and is not viable either.)