I'm trying to set up Blackberry Internet Service to connect to our Windows SBS2003 outlook web access. I've tried every possible combination of credentials by I always get the same error:

An error occured during email account validation. Please check your information and try again. If the error persists please contact your System Administrator.

The fields are the following:

Outlook Web Access URL: http://mail.domain.com/exchange (I've also tried just using the IP address http://000.000.000.000/exchange with no effect).

User Name: JohnDoe (same as OWA login / domain username - I've also tried DOMAIN\JohnDoe)

Email Address: [email protected]

Mailbox Name: This one confused me a little bit, but it seems it should be the same as the domain username (eg. JohnDoe). I've also tried DOMAIN\JohnDoe, and a number of other things.

No matter what I do, I get the same error message. At this point, I'm basically just trying things, because I don't really know how this service is supposed to work. Does anyone know what causes this particularly vague error message, and what I can change either in my email settings or on our exchange server to resolve this?