After Installing Microsoft Exchange Server 2003 on a Windows Server 2003, OWA was not working, After checking the ISS Manager folder structure, I got the following error when trying to open the Exchange directory.
You can follow this article to solve.
https://ittutorials.net/microsoft/exchange-2003/fixing-backofficestorage-mbx-is-not-accessible-error-when-opening-owa-folders/
