Postfix manual - qmgr(8)

From b5896ba9f6047e7031e2bdee0622d543e11a6734 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:46:30 +0200 Subject: Adding upstream version 3.4.23. Signed-off-by: Daniel Baumann --- html/qmgr.8.html | 502 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 502 insertions(+) create mode 100644 html/qmgr.8.html (limited to 'html/qmgr.8.html') diff --git a/html/qmgr.8.html b/html/qmgr.8.html new file mode 100644 index 0000000..3497b3b --- /dev/null +++ b/html/qmgr.8.html @@ -0,0 +1,502 @@ + + + + Postfix manual - qmgr(8) +
+QMGR(8)                                                                QMGR(8)
+
+NAME
+       qmgr - Postfix queue manager
+
+SYNOPSIS
+       qmgr [generic Postfix daemon options]
+
+DESCRIPTION
+       The qmgr(8) daemon awaits the arrival of incoming mail and arranges for
+       its delivery via Postfix delivery processes.  The actual  mail  routing
+       strategy  is  delegated to the trivial-rewrite(8) daemon.  This program
+       expects to be run from the master(8) process manager.
+
+       Mail addressed to the local double-bounce address is  logged  and  dis-
+       carded.   This  stops  potential  loops  caused by undeliverable bounce
+       notifications.
+
+MAIL QUEUES
+       The qmgr(8) daemon maintains the following queues:
+
+       incoming
+              Inbound mail from the network, or mail picked up  by  the  local
+              pickup(8) daemon from the maildrop directory.
+
+       active Messages  that the queue manager has opened for delivery. Only a
+              limited number of messages is allowed to enter the active  queue
+              (leaky bucket strategy, for a fixed delivery rate).
+
+       deferred
+              Mail  that  could  not  be delivered upon the first attempt. The
+              queue manager implements exponential  backoff  by  doubling  the
+              time between delivery attempts.
+
+       corrupt
+              Unreadable or damaged queue files are moved here for inspection.
+
+       hold   Messages that are kept "on hold" are  kept  here  until  someone
+              sets them free.
+
+DELIVERY STATUS REPORTS
+       The  qmgr(8) daemon keeps an eye on per-message delivery status reports
+       in the following directories. Each status report file has the same name
+       as the corresponding message file:
+
+       bounce Per-recipient  status  information  about  why  mail is bounced.
+              These files are maintained by the bounce(8) daemon.
+
+       defer  Per-recipient status information  about  why  mail  is  delayed.
+              These files are maintained by the defer(8) daemon.
+
+       trace  Per-recipient  status  information as requested with the Postfix
+              "sendmail -v" or "sendmail -bv" command.  These files are  main-
+              tained by the trace(8) daemon.
+
+       The qmgr(8) daemon is responsible for asking the bounce(8), defer(8) or
+       trace(8) daemons to send delivery reports.
+
+STRATEGIES
+       The queue manager implements a variety of strategies for either opening
+       queue files (input) or for message delivery (output).
+
+       leaky bucket
+              This  strategy limits the number of messages in the active queue
+              and prevents the queue manager from running out of memory  under
+              heavy load.
+
+       fairness
+              When the active queue has room, the queue manager takes one mes-
+              sage from the incoming queue and one from  the  deferred  queue.
+              This prevents a large mail backlog from blocking the delivery of
+              new mail.
+
+       slow start
+              This strategy eliminates "thundering herd"  problems  by  slowly
+              adjusting the number of parallel deliveries to the same destina-
+              tion.
+
+       round robin
+              The  queue  manager  sorts  delivery  requests  by  destination.
+              Round-robin  selection  prevents one destination from dominating
+              deliveries to other destinations.
+
+       exponential backoff
+              Mail  that  cannot  be  delivered  upon  the  first  attempt  is
+              deferred.   The  time interval between delivery attempts is dou-
+              bled after each attempt.
+
+       destination status cache
+              The queue manager avoids unnecessary delivery attempts by  main-
+              taining  a  short-term,  in-memory  list of unreachable destina-
+              tions.
+
+       preemptive message scheduling
+              The queue manager attempts to minimize the average per-recipient
+              delay  while  still  preserving  the correct per-message delays,
+              using a sophisticated preemptive message scheduling.
+
+TRIGGERS
+       On an idle system, the queue manager waits for the arrival  of  trigger
+       events, or it waits for a timer to go off. A trigger is a one-byte mes-
+       sage.  Depending on the message received, the  queue  manager  performs
+       one  of  the following actions (the message is followed by the symbolic
+       constant used internally by the software):
+
+       D (QMGR_REQ_SCAN_DEFERRED)
+              Start a deferred queue  scan.   If  a  deferred  queue  scan  is
+              already  in  progress, that scan will be restarted as soon as it
+              finishes.
+
+       I (QMGR_REQ_SCAN_INCOMING)
+              Start an incoming queue scan.  If  an  incoming  queue  scan  is
+              already  in  progress, that scan will be restarted as soon as it
+              finishes.
+
+       A (QMGR_REQ_SCAN_ALL)
+              Ignore deferred queue file time stamps. The request affects  the
+              next deferred queue scan.
+
+       F (QMGR_REQ_FLUSH_DEAD)
+              Purge all information about dead transports and destinations.
+
+       W (TRIGGER_REQ_WAKEUP)
+              Wakeup  call,  This  is used by the master server to instantiate
+              servers that should not go away forever. The action is to  start
+              an incoming queue scan.
+
+       The  qmgr(8) daemon reads an entire buffer worth of triggers.  Multiple
+       identical trigger requests are collapsed into one, and trigger requests
+       are  sorted  so that A and F precede D and I. Thus, in order to force a
+       deferred queue run, one would request A F D; in  order  to  notify  the
+       queue manager of the arrival of new mail one would request I.
+
+STANDARDS
+       RFC 3463 (Enhanced status codes)
+       RFC 3464 (Delivery status notifications)
+
+SECURITY
+       The qmgr(8) daemon is not security sensitive. It reads single-character
+       messages from untrusted local users, and thus  may  be  susceptible  to
+       denial of service attacks. The qmgr(8) daemon does not talk to the out-
+       side world, and it can be run at fixed  low  privilege  in  a  chrooted
+       environment.
+
+DIAGNOSTICS
+       Problems  and  transactions  are  logged  to syslogd(8) or postlogd(8).
+       Corrupted message files are saved to  the  corrupt  queue  for  further
+       inspection.
+
+       Depending  on the setting of the notify_classes parameter, the postmas-
+       ter is notified of bounces and of other trouble.
+
+BUGS
+       A single queue manager process has to compete for disk access with mul-
+       tiple front-end processes such as cleanup(8). A sudden burst of inbound
+       mail can negatively impact outbound delivery rates.
+
+CONFIGURATION PARAMETERS
+       Changes to main.cf are not picked up automatically as qmgr(8) is a per-
+       sistent process. Use the "postfix reload" command after a configuration
+       change.
+
+       The text below provides only a parameter summary. See  postconf(5)  for
+       more details including examples.
+
+       In the text below, transport is the first field in a master.cf entry.
+
+COMPATIBILITY CONTROLS
+       Available before Postfix version 2.5:
+
+       allow_min_user (no)
+              Allow  a  sender  or  recipient address to have `-' as the first
+              character.
+
+       Available with Postfix version 2.7 and later:
+
+       default_filter_nexthop (empty)
+              When a content_filter or FILTER request  specifies  no  explicit
+              next-hop  destination, use $default_filter_nexthop instead; when
+              that value is empty, use the domain in the recipient address.
+
+ACTIVE QUEUE CONTROLS
+       qmgr_clog_warn_time (300s)
+              The minimal delay between warnings that a  specific  destination
+              is clogging up the Postfix active queue.
+
+       qmgr_message_active_limit (20000)
+              The maximal number of messages in the active queue.
+
+       qmgr_message_recipient_limit (20000)
+              The  maximal  number of recipients held in memory by the Postfix
+              queue manager, and the maximal size of the short-term, in-memory
+              "dead" destination status cache.
+
+       qmgr_message_recipient_minimum (10)
+              The minimal number of in-memory recipients for any message.
+
+       default_recipient_limit (20000)
+              The default per-transport upper limit on the number of in-memory
+              recipients.
+
+       transport_recipient_limit ($default_recipient_limit)
+              A transport-specific override  for  the  default_recipient_limit
+              parameter  value,  where  transport is the master.cf name of the
+              message delivery transport.
+
+       default_extra_recipient_limit (1000)
+              The default value for the extra per-transport limit  imposed  on
+              the number of in-memory recipients.
+
+       transport_extra_recipient_limit ($default_extra_recipient_limit)
+              A  transport-specific  override  for  the  default_extra_recipi-
+              ent_limit parameter value, where transport is the master.cf name
+              of the message delivery transport.
+
+       Available in Postfix version 2.4 and later:
+
+       default_recipient_refill_limit (100)
+              The  default  per-transport  limit  on  the number of recipients
+              refilled at once.
+
+       transport_recipient_refill_limit ($default_recipient_refill_limit)
+              A   transport-specific   override   for   the    default_recipi-
+              ent_refill_limit  parameter  value,  where transport is the mas-
+              ter.cf name of the message delivery transport.
+
+       default_recipient_refill_delay (5s)
+              The  default  per-transport  maximum  delay  between  recipients
+              refills.
+
+       transport_recipient_refill_delay ($default_recipient_refill_delay)
+              A    transport-specific   override   for   the   default_recipi-
+              ent_refill_delay parameter value, where transport  is  the  mas-
+              ter.cf name of the message delivery transport.
+
+DELIVERY CONCURRENCY CONTROLS
+       initial_destination_concurrency (5)
+              The  initial  per-destination  concurrency  level  for  parallel
+              delivery to the same destination.
+
+       default_destination_concurrency_limit (20)
+              The default maximal number of parallel deliveries  to  the  same
+              destination.
+
+       transport_destination_concurrency_limit   ($default_destination_concur-
+       rency_limit)
+              A  transport-specific  override for the default_destination_con-
+              currency_limit parameter value, where transport is the master.cf
+              name of the message delivery transport.
+
+       Available in Postfix version 2.5 and later:
+
+       transport_initial_destination_concurrency ($initial_destination_concur-
+       rency)
+              A  transport-specific  override for the initial_destination_con-
+              currency parameter value, where transport is the master.cf  name
+              of the message delivery transport.
+
+       default_destination_concurrency_failed_cohort_limit (1)
+              How  many  pseudo-cohorts  must  suffer  connection or handshake
+              failure before a specific destination is considered  unavailable
+              (and further delivery is suspended).
+
+       transport_destination_concurrency_failed_cohort_limit  ($default_desti-
+       nation_concurrency_failed_cohort_limit)
+              A  transport-specific  override for the default_destination_con-
+              currency_failed_cohort_limit parameter value, where transport is
+              the master.cf name of the message delivery transport.
+
+       default_destination_concurrency_negative_feedback (1)
+              The  per-destination  amount  of  delivery  concurrency negative
+              feedback, after a delivery completes with a connection or  hand-
+              shake failure.
+
+       transport_destination_concurrency_negative_feedback  ($default_destina-
+       tion_concurrency_negative_feedback)
+              A  transport-specific  override for the default_destination_con-
+              currency_negative_feedback parameter value, where  transport  is
+              the master.cf name of the message delivery transport.
+
+       default_destination_concurrency_positive_feedback (1)
+              The  per-destination  amount  of  delivery  concurrency positive
+              feedback, after a delivery completes without connection or hand-
+              shake failure.
+
+       transport_destination_concurrency_positive_feedback  ($default_destina-
+       tion_concurrency_positive_feedback)
+              A  transport-specific  override for the default_destination_con-
+              currency_positive_feedback parameter value, where  transport  is
+              the master.cf name of the message delivery transport.
+
+       destination_concurrency_feedback_debug (no)
+              Make  the queue manager's feedback algorithm verbose for perfor-
+              mance analysis purposes.
+
+RECIPIENT SCHEDULING CONTROLS
+       default_destination_recipient_limit (50)
+              The default maximal number of recipients per message delivery.
+
+       transport_destination_recipient_limit     ($default_destination_recipi-
+       ent_limit)
+              A transport-specific override for the default_destination_recip-
+              ient_limit  parameter  value,  where  transport is the master.cf
+              name of the message delivery transport.
+
+MESSAGE SCHEDULING CONTROLS
+       default_delivery_slot_cost (5)
+              How often the Postfix queue manager's scheduler  is  allowed  to
+              preempt delivery of one message with another.
+
+       transport_delivery_slot_cost ($default_delivery_slot_cost)
+              A transport-specific override for the default_delivery_slot_cost
+              parameter value, where transport is the master.cf  name  of  the
+              message delivery transport.
+
+       default_minimum_delivery_slots (3)
+              How  many  recipients a message must have in order to invoke the
+              Postfix queue manager's scheduling algorithm at all.
+
+       transport_minimum_delivery_slots ($default_minimum_delivery_slots)
+              A transport-specific  override  for  the  default_minimum_deliv-
+              ery_slots parameter value, where transport is the master.cf name
+              of the message delivery transport.
+
+       default_delivery_slot_discount (50)
+              The default value for transport-specific _delivery_slot_discount
+              settings.
+
+       transport_delivery_slot_discount ($default_delivery_slot_discount)
+              A transport-specific override for the default_delivery_slot_dis-
+              count parameter value, where transport is the master.cf name  of
+              the message delivery transport.
+
+       default_delivery_slot_loan (3)
+              The  default  value  for  transport-specific _delivery_slot_loan
+              settings.
+
+       transport_delivery_slot_loan ($default_delivery_slot_loan)
+              A transport-specific override for the default_delivery_slot_loan
+              parameter  value,  where  transport is the master.cf name of the
+              message delivery transport.
+
+OTHER RESOURCE AND RATE CONTROLS
+       minimal_backoff_time (300s)
+              The minimal time between attempts to deliver a deferred message;
+              prior to Postfix 2.4 the default value was 1000s.
+
+       maximal_backoff_time (4000s)
+              The maximal time between attempts to deliver a deferred message.
+
+       maximal_queue_lifetime (5d)
+              Consider a message as undeliverable, when delivery fails with  a
+              temporary error, and the time in the queue has reached the maxi-
+              mal_queue_lifetime limit.
+
+       queue_run_delay (300s)
+              The time between deferred queue  scans  by  the  queue  manager;
+              prior to Postfix 2.4 the default value was 1000s.
+
+       transport_retry_time (60s)
+              The  time  between attempts by the Postfix queue manager to con-
+              tact a malfunctioning message delivery transport.
+
+       Available in Postfix version 2.1 and later:
+
+       bounce_queue_lifetime (5d)
+              Consider a bounce message as undeliverable, when delivery  fails
+              with  a  temporary  error, and the time in the queue has reached
+              the bounce_queue_lifetime limit.
+
+       Available in Postfix version 2.5 and later:
+
+       default_destination_rate_delay (0s)
+              The default amount of delay that is inserted between  individual
+              message  deliveries  to  the  same destination and over the same
+              message delivery transport.
+
+       transport_destination_rate_delay ($default_destination_rate_delay)
+              A   transport-specific   override   for   the   default_destina-
+              tion_rate_delay  parameter  value,  where  transport is the mas-
+              ter.cf name of the message delivery transport.
+
+       Available in Postfix version 3.1 and later:
+
+       default_transport_rate_delay (0s)
+              The default amount of delay that is inserted between  individual
+              message  deliveries  over  the  same message delivery transport,
+              regardless of destination.
+
+       transport_transport_rate_delay ($default_transport_rate_delay)
+              A   transport-specific   override   for    the    default_trans-
+              port_rate_delay  parameter value, where the initial transport in
+              the parameter name is the master.cf name of the message delivery
+              transport.
+
+SAFETY CONTROLS
+       qmgr_daemon_timeout (1000s)
+              How much time a Postfix queue manager process may take to handle
+              a request before it is terminated by a built-in watchdog  timer.
+
+       qmgr_ipc_timeout (60s)
+              The time limit for the queue manager to send or receive informa-
+              tion over an internal communication channel.
+
+       Available in Postfix version 3.1 and later:
+
+       address_verify_pending_request_limit (see 'postconf -d' output)
+              A safety limit that prevents address verification requests  from
+              overwhelming the Postfix queue.
+
+MISCELLANEOUS CONTROLS
+       config_directory (see 'postconf -d' output)
+              The  default  location of the Postfix main.cf and master.cf con-
+              figuration files.
+
+       defer_transports (empty)
+              The names of message delivery transports that should not deliver
+              mail unless someone issues "sendmail -q" or equivalent.
+
+       delay_logging_resolution_limit (2)
+              The  maximal  number of digits after the decimal point when log-
+              ging sub-second delay values.
+
+       helpful_warnings (yes)
+              Log warnings about problematic configuration settings, and  pro-
+              vide helpful suggestions.
+
+       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 (see 'postconf -d' output)
+              A  prefix  that  is  prepended  to  the  process  name in syslog
+              records, so that, for example, "smtpd" becomes "prefix/smtpd".
+
+       Available in Postfix version 3.0 and later:
+
+       confirm_delay_cleared (no)
+              After sending a "your message is delayed"  notification,  inform
+              the sender when the delay clears up.
+
+       Available in Postfix 3.3 and later:
+
+       service_name (read-only)
+              The master.cf service name of a Postfix daemon process.
+
+FILES
+       /var/spool/postfix/incoming, incoming queue
+       /var/spool/postfix/active, active queue
+       /var/spool/postfix/deferred, deferred queue
+       /var/spool/postfix/bounce, non-delivery status
+       /var/spool/postfix/defer, non-delivery status
+       /var/spool/postfix/trace, delivery status
+
+SEE ALSO
+       trivial-rewrite(8), address routing
+       bounce(8), delivery status reports
+       postconf(5), configuration parameters
+       master(5), generic daemon options
+       master(8), process manager
+       postlogd(8), Postfix logging
+       syslogd(8), system logging
+
+README FILES
+       SCHEDULER_README, scheduling algorithm
+       QSHAPE_README, Postfix queue analysis
+
+LICENSE
+       The Secure Mailer license must be distributed with this software.
+
+AUTHOR(S)
+       Wietse Venema
+       IBM T.J. Watson Research
+       P.O. Box 704
+       Yorktown Heights, NY 10598, USA
+
+       Preemptive scheduler enhancements:
+       Patrik Rak
+       Modra 6
+       155 00, Prague, Czech Republic
+
+       Wietse Venema
+       Google, Inc.
+       111 8th Avenue
+       New York, NY 10011, USA
+
+                                                                       QMGR(8)
+
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