The Microsoft article "XCCC: A New Option that Allows Exchange 2000 Server and OWA to Always Use SSL (HTTPS)" at http://support.microsoft.com/?kbid=327800 describes a special .dll file, ExFeHttpsOnFilter, that you must install on servers that are behind Secure Sockets Layer (SSL) hardware accelerators to keep the URLs generated by the front-end and back-end servers in sync. Does this filter also apply to Exchange Server 2003?

Yes, Exchange 2003 supports the filter—see the Microsoft article for details about where to get it and how to install it. The .dll file is actually an Internet Server API (ISAPI) filter that addresses the problem that occurs with SSL off-loading in a front-end/back-end configuration. Specifically, the front-end server doesn't recognize that the Outlook Web Access (OWA) client is using SSL because the connection between the off-load device and the front-end server isn't using SSL (i.e., the front-end server doesn't know that it should be prepending "https" to URLs it sends instead of just adding "http").