This is probably not what is desired, though it may be a part of it.
A not very long time ago, I also cared about keeping gnus and mh in
sync.  For incoming stuff, if I used MH to inc a folder, I had as part
of my gnus-select-group-hook (I think, though it may have been a
different hook) a call to nnml-generate-nov-databases-1.  Then, to
have gnus update the unseen sequence, I used the lisp found at the end
of this message.  If gnus incorporated the mail (which was becoming
more and more the normal case) I punted on the unseen sequence stuff.
I wanted to get it done, but none of the advices I put on the
nnml-accept functions ever seemed to work reliably.  For what its
worth, back then (I'm pretty sure the last time I ever bothered with
this, it was still September) nnmh didn't do anything with the mh
sequences either (does it now?).  Anyway, if this helps someone make
gnus deal better with mh, so much the better.  If not, I apologize for
the waste of bandwidth.

--
Dave Goldberg
Post: The Mitre Corporation\MS B305\202 Burlington Rd.\Bedford, MA 01730
Phone: 617-271-3887
Email: dsg@mitre.org