Their "Mail" in OSX application runs the Exchange (2010) account just fine.
But when we go to the same Exchange account for the user on their Mac (Outlook 2011), it appears to accept the credentials to add the account, but they end up getting the error after trying to send/receive mail.
The server for account "Mail" returned the error "Logon failure: unknown user name or bad password." Your username/password or security settings may be incorrect. Would you like to try re-entering your password?
So I'm not sure if this error is for adding the account, or if the account was successfully added and it's just a send/receive issue.
We've tried adding the account with the username, UPN, localdomain\username, and server info we've tried fqdn of mailbox server, client access server, external/internal URL, etc. but no success.
They can login to OWA web mail login just fine so we know their username/password is correct.
And as stated before, the built-in "Mail" program for OS X runs the Exchange account just fine.