Ever since we migrated to Exchange Server 2003, Outlook Web Access (OWA) seems to be broken. Our OWA users just get a message that says Loading instead of mail content. What's going on?
The problem has several potential causes. Perhaps you've read the Microsoft article "Troubleshooting OWA when the contents frame displays 'Loading'" (http://support.microsoft.com/?kbid=280823), which outlines potential causes and solutions for the problem you describe, but because in your case the problem didn't start until you deployed Exchange 2003, I doubt that those solutions will apply to you. Your problem more likely involves a conflict between two otherwise useful features: forms-based authentication and compression for OWA pages. When both features are turned on, a bug in Microsoft Internet Information Services (IIS) 6.0 can cause it to mangle static pages—including the pages that OWA serves to users. Fortunately, a hotfix exists; see the Microsoft article "FIX: IIS 6.0 compression corruption causes access violations" (http://support.microsoft.com/?kbid=831464) for more information about the hotfix. In the meantime, you can work around the problem by turning off compression on your IIS server. (For more information about other potential problems involving forms-based authentication, see "Resolving Problems with Forms-Based Authentication," June 2004, InstantDoc ID 42233 and the Web-exclusive article "Forms-Based Authentication: Problems and Points Worth Noting," November 2003, InstantDoc ID 40821.)