We are using Exchange 2003. OWA was working fine last week and for the previous 6 months. Today OWA doesn't work. When we try to login as any user except for Administrator we get HTTP/1.1 403 Forbidden.
I tried the following already.
- Checked form based authentication
- Allow ASP to run.
- Checked all the security in IIS
- Installed latest Windows Updates
- Tried with Firefox and Internet Explorer.