
I ran into this issue the other day, where the My Inbox and My Calendar webparts in MOSS 2007 did not display properly. The users were getting HTTP 404 errors within the web parts. After some tinkering with the URL here is what we found to work:
- Set the URL to https://OWAURL/exchange
- Add this URL to the Trusted Sites Zone within IE - This can be pushed to clients using Group Policy
- Now set the mailbox information[ @domain.com for mailbox and for the calendar within the web part.
This helped solve the issue