For the mailing list, the headers had Sender: sqlite-users <sqlite-users-bounces@mailinglists.sqlite.org> and in Outlook for me they would show up as "sqlite-users on behalf of ..." and making a rule just for things from the sqlite-users address worked fine without needing to do any fancy searching or such. Forum emails don't seem to have that sender line anywhere. Maybe just putting that back would be the simplest solution.