Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.0.0) Gecko/20020530 Preferences "Advanced"->"System" has a check list "Windows should use Mozilla to handle these protocols". This list includes http, https, ftp, chrome, and gopher. Shouldn't it also include "news:"? As it is, although I have set the preference to "use Mozilla as the default mail application" ("Mail & News" pref tab), if I try to open a "news:" URL from outside Mozilla (e.g., through a command line: "rundll32 url.dll,FileProtocolHandler <a news: url>"), Windows will try to open it using Outlook.
*** This bug has been marked as a duplicate of 121369 ***