you must make sure that Autodiscover is configured correctly
On the none domain joined pc's start outlook and right click the outlook tray icon (lower right corner) while holding CTRL => select Test-Email autoconfiguration
This must succeed in order for OC to get to the exchange web services
More info on Autodiscover here
http://technet.microsoft.com/en-us/library/bb124251.aspx
- Belgian Exchange Community : http://www.pro-exchange.be -