Mail doesn't rescan automatically

[Geoff Kuenning <geoff@cs.hmc.edu>]

I'm using gnus primarily for mail.  I've got nearly everything working
the way I want it, except for one glitch: when I type "g"
(gnus-group-get-new-news) in the Groups buffer, it fetches new mail
and splits it into my chosen nnml folders, but doesn't rescan those
folders so that it can update the Groups display.

I've found that I can work around the problem by running M-g
(gnus-group-get-new-news-this-group), but that's unsatisfactory
because it requires me to walk through all my mail groups, polling
them to find out if new mail has been split into them.

I experimented a bit with gnus-activate-group, which requires a group
name, and with gnus-activate-all-groups, which doesn't seem to produce
the results I want.

I keep thinking there *must* be a config setting someplace that says
"always pay attention to new files that you just stuck into an nnml
directory".  But I can't find it, for the life of me.

Any hints?
-- 
    Geoff Kuenning   geoff@cs.hmc.edu   http://www.cs.hmc.edu/~geoff/

If at first you succeed, try to hide your astonishment.
	-- Harry F. Banks