OWANotifier is a free, easy to use and simple menu bar application that will give you Growl notifications whenever you get new mail from Outlook Web Access.

For those who’s company uses outlook, but you use a Mac at work, you will understand my pain. No Outlook for the Mac and Outlook Web Access does not notify you on new emails.

OWANotifier will at least notify you of the new emails (via Growl and an alert sound), but you will still have to use OWA to read the email.