To SMTP-reject messages without patching qmail-smtpd(8), compose the
following programs into your configuration as needed:

- qmail-qfilter-smtpd-queue is a QMAILQUEUE wrapper that runs
  qmail-qfilter with the sequence of programs in control/smtpfilters,
  rejecting if any of them reject.
- qmail-qfilter-ofmipd-queue is a QMAILQUEUE wrapper that runs
  qmail-qfilter with the sequence of programs in control/ofmipfilters,
  rejecting if any of them reject.
- qmail-qfilter-viruscan is the viruscan patch repackaged as a
  qmail-qfilter-compatible program.
- qmail-rcptcheck is a RCPTCHECK-compatible program that runs the
  sequence of programs in control/rcptchecks, rejecting if any of
  them reject.
- qmail-rcptcheck-realrcptto is the realrcptto patch repackaged as a
  RCPTCHECK-compatible program.
- qmail-rcptcheck-badrcptto is the badrcptto patch repackaged as a
  RCPTCHECK-compatible program.
- qmail-rcptcheck-qregex is (most of) the qregex patch repackaged as a
  RCPTCHECK-compatible program