showq - Unix, Linux Command

previous next AddThis Social Bookmark Button


showq - list the Postfix mail queue


showq [generic Postfix daemon options]


The showq(8) daemon reports the Postfix mail queue status. It is the program that emulates the sendmail ‘mailq’ command.

The showq(8) daemon can also be run in stand-alone mode by the superuser. This mode of operation is used to emulate the ‘mailq’ command while the Postfix mail system is down.


The showq(8) daemon can run in a chroot jail at fixed low privilege, and takes no input from the client. Its service port is accessible to local untrusted users, so the service can be susceptible to denial of service attacks.


None. The showq(8) daemon does not interact with the outside world.


Problems and transactions are logged to syslogd(8).


The showq(8) daemon runs at a fixed low privilege; consequently, it cannot extract information from queue files in the maildrop directory.


Changes to are picked up automatically as showq(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

config_directory (see ’postconf -d’ output) The default location of the Postfix and configuration files.
daemon_timeout (18000s) How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.
duplicate_filter_limit (1000) The maximal number of addresses remembered by the address duplicate filter for aliases(5) or virtual(5) alias expansion, or for showq(8) queue displays.
empty_address_recipient (MAILER-DAEMON) The recipient of mail addressed to the null address.
ipc_timeout (3600s) The time limit for sending or receiving information over an internal communication channel.
max_idle (100s) The maximum amount of time that an idle Postfix daemon process waits for the next service request before exiting.
max_use (100) The maximal number of connection requests before a Postfix daemon process terminates.
process_id (read-only) The process ID of a Postfix command or daemon process.
process_name (read-only) The process name of a Postfix command or daemon process.
queue_directory (see ’postconf -d’ output) The location of the Postfix top-level queue directory.
syslog_facility (mail) The syslog facility of Postfix logging.
syslog_name (postfix) The mail system name that is prepended to the process name in syslog records, so that "smtpd" becomes, for example, "postfix/smtpd".


/var/spool/postfix, queue directories


pickup(8), local mail pickup service
cleanup(8), canonicalize and enqueue mail
qmgr(8), queue manager
postconf(5), configuration parameters
master(8), process manager
syslogd(8), system logging


The Secure Mailer license must be distributed with this software.


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

previous next Printer Friendly