Tixy wrote: > I'm guessing the archive is falling back to threading by > matching the subject line, as with Curt's MUA? The Debian list admins will have a more authoritative answer then mine, but I searched a bit about "possible follow-ups" in and this [1] old posting by the author of MHonArc confirms your guess. Thomas [1] https://www.mhonarc.org/archive/html/mhonarc-users/1999-02/msg00029.html