See procmailex(5) and procmailrc(5).
:0 Wh: msgid.log | formail -D 65536 /home/perry/.msgid.cache
:0: * ^List-Post:.*<!mailto:\/[A-Za-z0-9][-A-Za-z0-9\.@]+ lists/$MATCH :0: * ^Sender: owner-\/[[A-Za-z0-9][[-A-Za-z0-9\.@]+ lists/$MATCH
2 pages link to ProcmailNotes: