So... #emacs #gnus - Would anyone know how to do any of the following with a prepopulated directory lacking a NOV file and containing around 442.000 emails in nml format?
a) rerun filtering on the directory to decrease the size of it (fancy-split works on *new* email) into Gnus view?
b) generate the NOV file for the directory without crashing emacs (tried with direct M-x nnml-generate-nov-databases-directory  but emacs crashed after a good while.
c) your idea here.