Outlook Web Access (OWA) for Exchange 2007 allows you to open other mailboxes when the entire mailbox is being shared between users. However, this feature does not allow you to access shared calendars or other individual folders.
1. To access a shared calendar via OWA, you need to copy the below address:
2. Replace example email address listed in the above link with the e-mail address for the user that has shared their calendar. This will display the OWA login page. Note that after you have entered your credentials, the shared calender will be displayed.