Unsubscribe from ALL Forum email?

My Webmail was converted to the new format today.  While checking out the new version, I opened a "Forums" folder I had created.  It contains Forum email notification messages that were moved to this folder by a Filter Rule I created.  I did this to monitor when these emails were being received while moving them out of sight of routine Webmail.  These emails were received even though I could not have chosen to get Forum email notifications because this feature has been disabled in Settings for over 5 years.  The most recent email was received a week ago.  This Filter Rule could just as easily have a "Discard" action which would eliminate ever having to see the Forum email notification messages at all.