postlock - lock mail folder and execute command

       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                                                     POSTLOCK(1)

       With  remote file systems, the ability to acquire a lock does not necessarily eliminate access conflicts.
       Avoid file access by processes running on different machines.

       The following main.cf parameters are especially relevant to this program.  The text below provides only a
       parameter summary. See postconf(5) for more details including examples.

       The  postlock(1)  command  locks  file  for exclusive access, and executes command. The locking method is
       compatible with the Postfix UNIX-style local delivery agent.

       Options:

       -cconfig_dir
              Read the main.cf configuration file in the named directory instead of  the  default  configuration
              directory.

       -llock_style
              Override  the  locking method specified via the mailbox_delivery_lock configuration parameter (see
              below).

       -v     Enable verbose logging for debugging purposes. Multiple -v options make the software  increasingly
              verbose.

       Arguments:

       file   A mailbox file. The user should have read/write permission.

       command...
              The  command  to  execute  while  file  is  locked  for exclusive access.  The command is executed
              directly, i.e. without interpretation by a shell command interpreter.

       The result status is 75 (EX_TEMPFAIL)  when  postlock(1)  could  not  perform  the  requested  operation.
       Otherwise, the exit status is the exit status from the command.

MAIL_CONFIG
              Directory with Postfix configuration files.

       MAIL_VERBOSE
              Enable verbose logging for debugging purposes.

       The Secure Mailer license must be distributed with this software.

deliver_lock_attempts(20)
              The maximal number of attempts to acquire an  exclusive  lock  on  a  mailbox  file  or  bounce(8)
              logfile.

       deliver_lock_delay(1s)
              The time between attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile.

       stale_lock_time(500s)
              The time after which a stale exclusive mailbox lockfile is removed.

       mailbox_delivery_lock(see'postconf-d'output)
              How to lock a UNIX-style local(8) mailbox before attempting delivery.

config_directory(see'postconf-d'output)
              The default location of the Postfix main.cf and master.cf configuration files.

       import_environment(see'postconf-d'output)
              The list of environment variables that a privileged Postfix process will import from a non-Postfix
              parent process, or name=value environment overrides.

       postlock - lock mail folder and execute command

fork_attempts(5)
              The maximal number of attempts to fork() a child process.

       fork_delay(1s)
              The delay between attempts to fork() a child process.

postconf(5), configuration parameters

postlock [-cconfig_dir] [-llock_style]
               [-v] filecommand...