Don't mutate the caller's argument.
|/usr/local/bin/ezmlm-weed
|/usr/local/bin/ezmlm-moderate '/tmp/woo/test'
|if test -f '/tmp/woo/test/threaded'; then /usr/local/bin/ezmlm-archive '/tmp/woo/test' || exit 0; fi
|/usr/local/bin/ezmlm-clean '/tmp/woo/test' || exit 0
|/usr/local/bin/ezmlm-warn '/tmp/woo/test' || exit 0