You need to either give hypermail an mbox which has all the messages that are in the archive (i.e. stop removing the mbox after you run hypermail), or use the incremental mode and add one message at a time. If you really need to send it several messages at a time, there's a script called hyperfeed.pl in the contrib directory which will split an mbox into single messages and feed them to hypermail, but for archives that are updated via nightly cron jobs I think it's better to keep a complete mbox somewhere (probably not in /var/spool/mail) for hypermail to use.
This archive was generated by hypermail 2.2.0 : Thu 22 Feb 2007 07:33:53 PM GMT GMT