Having never tried to use filters before I tried to use them in a newly installed version of 0.9.6. The Message Filter window appears, but clicking new does nothing. In the 'Filters for' tab there are no entries present. This might be related to bug 111149, but unlike the reporter in that bug I have not imported any filters from NS4.x as I have never tried to use them in any version of NS/mozilla before. It may be relevant that I have no mail accounts and only use the Mozilla mail/news component for browsing news - I wanted to use the filters to get rid of all the spam in the mozilla newsgroups.
what's more relevant is that this isn't implemented. the only question is should the ui not allow you to try or somehow explain why you can't do this. *** This bug has been marked as a duplicate of 16913 ***
Reopen bug and change summary. If the user has news accounts but no mail accounts, the "Edit: Message Filter" menu item should be disabled since the feature is not available.
*** This bug has been marked as a duplicate of 67219 ***
Marking verified as a duplicate.