address. If the message is successfully delivered, qmail-send marks the
address as DONE. If the delivery attempt meets with permanent failure,
qmail-send first appends a note to bounce/457, creating bounce/457 if
-necessary; then it marks the address as DONE.
+necessary; then it marks the address as DONE. Note that bounce/457 is
+not crashproof.
qmail-send may handle bounce/457 at any time, as follows: it (1) injects
a new bounce message, created from bounce/457 and mess/457; (2) deletes