qmail-newmrh reads the instructions in
/var/qmail/control/morercpthosts and writes them into
/var/qmail/control/morercpthosts.cdb in a binary format suited
for quick access by
If there is a problem with
qmail-newmrh complains and leaves
qmail-newmrh ensures that
control/morercpthosts.cdb is updated atomically,
qmail-smtpd never has to wait for
qmail-newmrh to finish.
qmail-newmrh makes no attempt to protect against two simultaneous updates of
control/morercpthosts.cdb format is portable across machines.