I dear Kenny, By now I'm running Outlook 2007 using my own Exchange 2003, I mean hosted in my own servers, controlled by my own domain, etc. I have no issues with this. Regarding your question, to me it's not a crossover problem, it's some sort of security and configuration problem, here are my recommendations:
-
First of all try con configure a "normal" windows client with the configuration file you have, it's important that the client be inside your network and with all the default options you do expect in your Ubuntu/Crossover configuration, if you succeed, then the problem it's inside your Ubuntu or your crossover or your outlook, on the other hand, if you cannot connect then the problem must be your client's configuration, network, firewall, internet connection/provider etc.
-
Then try to turn off any sort of protection software (iptables, ipfw, antispyware, etc.), then try to configure your service if you can, then there is a problem with your ports, try to figure out which ports your provider use and then open and verify that any of them are not blocked, one major problem with outlook it's that for some configurations it acquires two random ports for login/identification purposes, so can be difficult to configure the adequate security schema in order to grant the service connection.
As I wrote, to me there's not any problems with crossover + outlook 2003 + exchange 2003 server, I'm dealing with it for some time now with no major issues, my guess is that you have some closed ports and some security rules that are in the way of your outlook and your server.
Hope that helps.
Regards.
José Luis