#man  postsuper

NAME

       postsuper - Postfix superintendent

SYNOPSIS

       postsuper [-psv] [-c config_dir] [-d queue_id]

               [-h queue_id] [-H queue_id]

               [-r queue_id] [directory ...]

 -d queue_id

              Delete  one  message  with  the named queue ID from the named mail queue(s) (default: hold, incoming, active and

              deferred).

              If a queue_id of - is specified, the program reads queue IDs from standard input. For  example,  to  delete  all

              mail with exactly one recipient user@example.com:

              mailq | tail +2 | grep -v ’^ *(’ | awk  ′BEGIN { RS = "" }

                  # $7=sender, $8=recipient1, $9=recipient2

                  { if ($8 == "user@example.com" && $9 == "")

                        print $1 }

              ′ | tr -d ’*!’ | postsuper -d -

              Specify  "-d  ALL"  to  remove  all  messages;  for example, specify "-d ALL deferred" to delete all mail in the

              deferred queue.  As a safety measure, the word ALL must be specified in upper case.

              Warning: Postfix queue IDs are reused.  There is a very small possibility that postsuper deletes the wrong  mes-

              sage file when it is executed while the Postfix mail system is delivering mail.

              The scenario is as follows:

              1)     The  Postfix  queue  manager deletes the message that postsuper(1) is asked to delete, because Postfix is

                     finished with the message (it is delivered, or it is returned to the sender).

              2)     New mail arrives, and the new message is given the same queue ID as the message that postsuper(1) is sup-

                     posed  to delete.  The probability for reusing a deleted queue ID is about 1 in 2**15 (the number of dif-

                     ferent microsecond values that the system clock can distinguish within a second).

              3)     postsuper(1) deletes the new message, instead of the old message that it should have deleted.