scheme mail filter:

http://0xcc.net/scmail/index.html.en


more interesting examples:

automatically filter mails containing list-id header
debienna.rerun.lefant.net to l.net_lefant_rerun_debienna maildir folder

{{{
(add-filter-rule!
 '(list-id
   (#/<*([-.\w]+)\.([-\w]+)\.([-\w]+)\.([-\w]+)>*/ ".INBOX.l.\\4_\\3_\\2_\\1")
   (#/<*([-.\w]+)\.([-\w]+)\.([-\w]+)>*/ ".INBOX.l.\\3_\\2_\\1"))
}}}

and a more basic example: simply filter on From: address...
{{{
(add-filter-rule!
 '(from ("moin@lefant.net" ".INBOX.m.lewiki")))
}}}