We recently installed some Windows Server 2003 computers in our test lab. When I try to use Microsoft Outlook Web Access (OWA) from them, I occasionally have odd problems such as being prompted to reauthenticate when I open public folders. Do you know what the problem might be?
Windows 2003 includes many security enhancements. (For details about these enhancements, visit http://www.microsoft.com/technet/security/prodtech/windows/win2003/default.asp.) One of the new features, the Enhanced Security Configuration for Internet Explorer (ESCIE), locks down Microsoft Internet Explorer (IE) to keep server administrators from accidentally downloading malicious content. Unfortunately, ESCIE also prevents some OWA features (including attachment access) from working properly. To fix the problem, the Microsoft article "Various Issues With Attachments, Log On and Public Folders When Using Outlook Web Access on a Windows Server 2003-Based Computer" (http://support.microsoft.com/?kbid=820850) recommends that you add your OWA server to the list of trusted sites on the computer you're using. The article also recommends that you remove ESCIE, but I don't concur with that advice; you should leave it in place to ensure that your server's protected.
—Paul Robichaux