converting from nmh: how to?

[Greg Minshall <minshall@umich.edu>]

hi.  apologies if this is an FAQ.

i'm exploring notmuch (via the emacs front-end).  i have 1.2M e-mail
messages sorted into 200 or so nmh folders.  (*)

after running `notmuch new`, i end up with 1.2M "unread" messages, all
in "inbox".

i would like to end up with the "inbox" tag applied only to messages
actually in my nmh +inbox folder; messages from *other* nmh folders
should end up with a tag derived from that folder name.

and, i would like to have the "unread" tag only apply to messages that
nmh thinks are unseen.

(iiuc, nmh keeps track of unseen messages in ".mh_sequences" local to
each nmh folder; i don't think i care about any other sequences,
including "cur", in any of the ".mh_sequences" files.)

is there a known procedure for accomplishing this?  or, thoughts on
same?

cheers, Greg

(*) for the record, i use mpop and msmtp to receive and send e-mail, and
run things through procmail to sort mail into folders.  (and, another
procmail script to refile messages from, e.g., +inbox to some other
folder.)