that's your Org name in the URL. The reason that it includes the org name in the URL is because if there are different orgs, they all share the same url, just the org is different.
Was it working before and stopped working? Is it working if you go to the web URL in IE? If so, I would re-run the OUtlook configuration wizard (located start/programs/all programs/Microsoft Dynamics CRM 4.0/Configuration Wizard)
If it is not working when you go to the web client URL, there may be something wrong with your installation or the web site might not be running