Did you already try this ... Go to the advanced options to enter all the fields
Email Account: Name this whatever you want to see on your BB
Email: Your corporate email account in
(This would be the full email address)
User ID: Whatever login name you use to get to OWA
Password: Your OWA password for the above user name
Server: the OWA exchange server address....include the HTTPS
Email Account: the front part of your email address -.. from the example above 'yourname' would be in this box.