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diff --git a/man/man8/qmgr.8 b/man/man8/qmgr.8 new file mode 100644 index 0000000..a24af71 --- /dev/null +++ b/man/man8/qmgr.8 @@ -0,0 +1,495 @@ +.TH QMGR 8 +.ad +.fi +.SH NAME +qmgr +\- +Postfix queue manager +.SH "SYNOPSIS" +.na +.nf +\fBqmgr\fR [generic Postfix daemon options] +.SH DESCRIPTION +.ad +.fi +The \fBqmgr\fR(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 +\fBtrivial\-rewrite\fR(8) daemon. +This program expects to be run from the \fBmaster\fR(8) process +manager. + +Mail addressed to the local \fBdouble\-bounce\fR address is +logged and discarded. This stops potential loops caused by +undeliverable bounce notifications. +.SH "MAIL QUEUES" +.na +.nf +.ad +.fi +The \fBqmgr\fR(8) daemon maintains the following queues: +.IP \fBincoming\fR +Inbound mail from the network, or mail picked up by the +local \fBpickup\fR(8) daemon from the \fBmaildrop\fR directory. +.IP \fBactive\fR +Messages that the queue manager has opened for delivery. Only +a limited number of messages is allowed to enter the \fBactive\fR +queue (leaky bucket strategy, for a fixed delivery rate). +.IP \fBdeferred\fR +Mail that could not be delivered upon the first attempt. The queue +manager implements exponential backoff by doubling the time between +delivery attempts. +.IP \fBcorrupt\fR +Unreadable or damaged queue files are moved here for inspection. +.IP \fBhold\fR +Messages that are kept "on hold" are kept here until someone +sets them free. +.SH "DELIVERY STATUS REPORTS" +.na +.nf +.ad +.fi +The \fBqmgr\fR(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: +.IP \fBbounce\fR +Per\-recipient status information about why mail is bounced. +These files are maintained by the \fBbounce\fR(8) daemon. +.IP \fBdefer\fR +Per\-recipient status information about why mail is delayed. +These files are maintained by the \fBdefer\fR(8) daemon. +.IP \fBtrace\fR +Per\-recipient status information as requested with the +Postfix "\fBsendmail \-v\fR" or "\fBsendmail \-bv\fR" command. +These files are maintained by the \fBtrace\fR(8) daemon. +.PP +The \fBqmgr\fR(8) daemon is responsible for asking the +\fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemons to +send delivery reports. +.SH "STRATEGIES" +.na +.nf +.ad +.fi +The queue manager implements a variety of strategies for +either opening queue files (input) or for message delivery (output). +.IP "\fBleaky bucket\fR" +This strategy limits the number of messages in the \fBactive\fR queue +and prevents the queue manager from running out of memory under +heavy load. +.IP \fBfairness\fR +When the \fBactive\fR queue has room, the queue manager takes one +message from the \fBincoming\fR queue and one from the \fBdeferred\fR +queue. This prevents a large mail backlog from blocking the delivery +of new mail. +.IP "\fBslow start\fR" +This strategy eliminates "thundering herd" problems by slowly +adjusting the number of parallel deliveries to the same destination. +.IP "\fBround robin\fR" +The queue manager sorts delivery requests by destination. +Round\-robin selection prevents one destination from dominating +deliveries to other destinations. +.IP "\fBexponential backoff\fR" +Mail that cannot be delivered upon the first attempt is deferred. +The time interval between delivery attempts is doubled after each +attempt. +.IP "\fBdestination status cache\fR" +The queue manager avoids unnecessary delivery attempts by +maintaining a short\-term, in\-memory list of unreachable destinations. +.IP "\fBpreemptive message scheduling\fR" +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. +.SH "TRIGGERS" +.na +.nf +.ad +.fi +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 message. +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): +.IP "\fBD (QMGR_REQ_SCAN_DEFERRED)\fR" +Start a deferred queue scan. If a deferred queue scan is already +in progress, that scan will be restarted as soon as it finishes. +.IP "\fBI (QMGR_REQ_SCAN_INCOMING)\fR" +Start an incoming queue scan. If an incoming queue scan is already +in progress, that scan will be restarted as soon as it finishes. +.IP "\fBA (QMGR_REQ_SCAN_ALL)\fR" +Ignore deferred queue file time stamps. The request affects +the next deferred queue scan. +.IP "\fBF (QMGR_REQ_FLUSH_DEAD)\fR" +Purge all information about dead transports and destinations. +.IP "\fBW (TRIGGER_REQ_WAKEUP)\fR" +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. +.PP +The \fBqmgr\fR(8) daemon reads an entire buffer worth of triggers. +Multiple identical trigger requests are collapsed into one, and +trigger requests are sorted so that \fBA\fR and \fBF\fR precede +\fBD\fR and \fBI\fR. Thus, in order to force a deferred queue run, +one would request \fBA F D\fR; in order to notify the queue manager +of the arrival of new mail one would request \fBI\fR. +.SH "STANDARDS" +.na +.nf +RFC 3463 (Enhanced status codes) +RFC 3464 (Delivery status notifications) +.SH "SECURITY" +.na +.nf +.ad +.fi +The \fBqmgr\fR(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 \fBqmgr\fR(8) daemon +does not talk to the outside world, and it can be run at fixed low +privilege in a chrooted environment. +.SH DIAGNOSTICS +.ad +.fi +Problems and transactions are logged to \fBsyslogd\fR(8) +or \fBpostlogd\fR(8). +Corrupted message files are saved to the \fBcorrupt\fR queue +for further inspection. + +Depending on the setting of the \fBnotify_classes\fR parameter, +the postmaster is notified of bounces and of other trouble. +.SH BUGS +.ad +.fi +A single queue manager process has to compete for disk access with +multiple front\-end processes such as \fBcleanup\fR(8). A sudden burst of +inbound mail can negatively impact outbound delivery rates. +.SH "CONFIGURATION PARAMETERS" +.na +.nf +.ad +.fi +Changes to \fBmain.cf\fR are not picked up automatically +as \fBqmgr\fR(8) +is a persistent process. Use the "\fBpostfix reload\fR" command after +a configuration change. + +The text below provides only a parameter summary. See +\fBpostconf\fR(5) for more details including examples. + +In the text below, \fItransport\fR is the first field in a +\fBmaster.cf\fR entry. +.SH "COMPATIBILITY CONTROLS" +.na +.nf +.ad +.fi +Available before Postfix version 2.5: +.IP "\fBallow_min_user (no)\fR" +Allow a sender or recipient address to have `\-' as the first +character. +.PP +Available with Postfix version 2.7 and later: +.IP "\fBdefault_filter_nexthop (empty)\fR" +When a content_filter or FILTER request specifies no explicit +next\-hop destination, use $default_filter_nexthop instead; when +that value is empty, use the domain in the recipient address. +.SH "ACTIVE QUEUE CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBqmgr_clog_warn_time (300s)\fR" +The minimal delay between warnings that a specific destination is +clogging up the Postfix active queue. +.IP "\fBqmgr_message_active_limit (20000)\fR" +The maximal number of messages in the active queue. +.IP "\fBqmgr_message_recipient_limit (20000)\fR" +The maximal number of recipients held in memory by the Postfix +queue manager, and the maximal size of the short\-term, +in\-memory "dead" destination status cache. +.IP "\fBqmgr_message_recipient_minimum (10)\fR" +The minimal number of in\-memory recipients for any message. +.IP "\fBdefault_recipient_limit (20000)\fR" +The default per\-transport upper limit on the number of in\-memory +recipients. +.IP "\fBtransport_recipient_limit ($default_recipient_limit)\fR" +A transport\-specific override for the default_recipient_limit +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_extra_recipient_limit (1000)\fR" +The default value for the extra per\-transport limit imposed on the +number of in\-memory recipients. +.IP "\fBtransport_extra_recipient_limit ($default_extra_recipient_limit)\fR" +A transport\-specific override for the default_extra_recipient_limit +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.PP +Available in Postfix version 2.4 and later: +.IP "\fBdefault_recipient_refill_limit (100)\fR" +The default per\-transport limit on the number of recipients refilled at +once. +.IP "\fBtransport_recipient_refill_limit ($default_recipient_refill_limit)\fR" +A transport\-specific override for the default_recipient_refill_limit +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_recipient_refill_delay (5s)\fR" +The default per\-transport maximum delay between recipients refills. +.IP "\fBtransport_recipient_refill_delay ($default_recipient_refill_delay)\fR" +A transport\-specific override for the default_recipient_refill_delay +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.SH "DELIVERY CONCURRENCY CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBinitial_destination_concurrency (5)\fR" +The initial per\-destination concurrency level for parallel delivery +to the same destination. +.IP "\fBdefault_destination_concurrency_limit (20)\fR" +The default maximal number of parallel deliveries to the same +destination. +.IP "\fBtransport_destination_concurrency_limit ($default_destination_concurrency_limit)\fR" +A transport\-specific override for the +default_destination_concurrency_limit parameter value, where +\fItransport\fR is the master.cf name of the message delivery +transport. +.PP +Available in Postfix version 2.5 and later: +.IP "\fBtransport_initial_destination_concurrency ($initial_destination_concurrency)\fR" +A transport\-specific override for the initial_destination_concurrency +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_destination_concurrency_failed_cohort_limit (1)\fR" +How many pseudo\-cohorts must suffer connection or handshake +failure before a specific destination is considered unavailable +(and further delivery is suspended). +.IP "\fBtransport_destination_concurrency_failed_cohort_limit ($default_destination_concurrency_failed_cohort_limit)\fR" +A transport\-specific override for the +default_destination_concurrency_failed_cohort_limit parameter value, +where \fItransport\fR is the master.cf name of the message delivery +transport. +.IP "\fBdefault_destination_concurrency_negative_feedback (1)\fR" +The per\-destination amount of delivery concurrency negative +feedback, after a delivery completes with a connection or handshake +failure. +.IP "\fBtransport_destination_concurrency_negative_feedback ($default_destination_concurrency_negative_feedback)\fR" +A transport\-specific override for the +default_destination_concurrency_negative_feedback parameter value, +where \fItransport\fR is the master.cf name of the message delivery +transport. +.IP "\fBdefault_destination_concurrency_positive_feedback (1)\fR" +The per\-destination amount of delivery concurrency positive +feedback, after a delivery completes without connection or handshake +failure. +.IP "\fBtransport_destination_concurrency_positive_feedback ($default_destination_concurrency_positive_feedback)\fR" +A transport\-specific override for the +default_destination_concurrency_positive_feedback parameter value, +where \fItransport\fR is the master.cf name of the message delivery +transport. +.IP "\fBdestination_concurrency_feedback_debug (no)\fR" +Make the queue manager's feedback algorithm verbose for performance +analysis purposes. +.SH "RECIPIENT SCHEDULING CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBdefault_destination_recipient_limit (50)\fR" +The default maximal number of recipients per message delivery. +.IP "\fBtransport_destination_recipient_limit ($default_destination_recipient_limit)\fR" +A transport\-specific override for the +default_destination_recipient_limit parameter value, where +\fItransport\fR is the master.cf name of the message delivery +transport. +.SH "MESSAGE SCHEDULING CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBdefault_delivery_slot_cost (5)\fR" +How often the Postfix queue manager's scheduler is allowed to +preempt delivery of one message with another. +.IP "\fBtransport_delivery_slot_cost ($default_delivery_slot_cost)\fR" +A transport\-specific override for the default_delivery_slot_cost +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_minimum_delivery_slots (3)\fR" +How many recipients a message must have in order to invoke the +Postfix queue manager's scheduling algorithm at all. +.IP "\fBtransport_minimum_delivery_slots ($default_minimum_delivery_slots)\fR" +A transport\-specific override for the default_minimum_delivery_slots +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_delivery_slot_discount (50)\fR" +The default value for transport\-specific _delivery_slot_discount +settings. +.IP "\fBtransport_delivery_slot_discount ($default_delivery_slot_discount)\fR" +A transport\-specific override for the default_delivery_slot_discount +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.IP "\fBdefault_delivery_slot_loan (3)\fR" +The default value for transport\-specific _delivery_slot_loan +settings. +.IP "\fBtransport_delivery_slot_loan ($default_delivery_slot_loan)\fR" +A transport\-specific override for the default_delivery_slot_loan +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.SH "OTHER RESOURCE AND RATE CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBminimal_backoff_time (300s)\fR" +The minimal time between attempts to deliver a deferred message; +prior to Postfix 2.4 the default value was 1000s. +.IP "\fBmaximal_backoff_time (4000s)\fR" +The maximal time between attempts to deliver a deferred message. +.IP "\fBmaximal_queue_lifetime (5d)\fR" +Consider a message as undeliverable, when delivery fails with a +temporary error, and the time in the queue has reached the +maximal_queue_lifetime limit. +.IP "\fBqueue_run_delay (300s)\fR" +The time between deferred queue scans by the queue manager; +prior to Postfix 2.4 the default value was 1000s. +.IP "\fBtransport_retry_time (60s)\fR" +The time between attempts by the Postfix queue manager to contact +a malfunctioning message delivery transport. +.PP +Available in Postfix version 2.1 and later: +.IP "\fBbounce_queue_lifetime (5d)\fR" +Consider a bounce message as undeliverable, when delivery fails +with a temporary error, and the time in the queue has reached the +bounce_queue_lifetime limit. +.PP +Available in Postfix version 2.5 and later: +.IP "\fBdefault_destination_rate_delay (0s)\fR" +The default amount of delay that is inserted between individual +message deliveries to the same destination and over the same message +delivery transport. +.IP "\fBtransport_destination_rate_delay ($default_destination_rate_delay)\fR" +A transport\-specific override for the default_destination_rate_delay +parameter value, where \fItransport\fR is the master.cf name of +the message delivery transport. +.PP +Available in Postfix version 3.1 and later: +.IP "\fBdefault_transport_rate_delay (0s)\fR" +The default amount of delay that is inserted between individual +message deliveries over the same message delivery transport, +regardless of destination. +.IP "\fBtransport_transport_rate_delay ($default_transport_rate_delay)\fR" +A transport\-specific override for the default_transport_rate_delay +parameter value, where the initial \fItransport\fR in the parameter +name is the master.cf name of the message delivery transport. +.SH "SAFETY CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBqmgr_daemon_timeout (1000s)\fR" +How much time a Postfix queue manager process may take to handle +a request before it is terminated by a built\-in watchdog timer. +.IP "\fBqmgr_ipc_timeout (60s)\fR" +The time limit for the queue manager to send or receive information +over an internal communication channel. +.PP +Available in Postfix version 3.1 and later: +.IP "\fBaddress_verify_pending_request_limit (see 'postconf -d' output)\fR" +A safety limit that prevents address verification requests from +overwhelming the Postfix queue. +.SH "MISCELLANEOUS CONTROLS" +.na +.nf +.ad +.fi +.IP "\fBconfig_directory (see 'postconf -d' output)\fR" +The default location of the Postfix main.cf and master.cf +configuration files. +.IP "\fBdefer_transports (empty)\fR" +The names of message delivery transports that should not deliver mail +unless someone issues "\fBsendmail \-q\fR" or equivalent. +.IP "\fBdelay_logging_resolution_limit (2)\fR" +The maximal number of digits after the decimal point when logging +sub\-second delay values. +.IP "\fBhelpful_warnings (yes)\fR" +Log warnings about problematic configuration settings, and provide +helpful suggestions. +.IP "\fBprocess_id (read\-only)\fR" +The process ID of a Postfix command or daemon process. +.IP "\fBprocess_name (read\-only)\fR" +The process name of a Postfix command or daemon process. +.IP "\fBqueue_directory (see 'postconf -d' output)\fR" +The location of the Postfix top\-level queue directory. +.IP "\fBsyslog_facility (mail)\fR" +The syslog facility of Postfix logging. +.IP "\fBsyslog_name (see 'postconf -d' output)\fR" +A prefix that is prepended to the process name in syslog +records, so that, for example, "smtpd" becomes "prefix/smtpd". +.PP +Available in Postfix version 3.0 and later: +.IP "\fBconfirm_delay_cleared (no)\fR" +After sending a "your message is delayed" notification, inform +the sender when the delay clears up. +.PP +Available in Postfix 3.3 and later: +.IP "\fBservice_name (read\-only)\fR" +The master.cf service name of a Postfix daemon process. +.PP +Available in Postfix 3.5 and later: +.IP "\fBinfo_log_address_format (external)\fR" +The email address form that will be used in non\-debug logging +(info, warning, etc.). +.SH "FILES" +.na +.nf +/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 +.SH "SEE ALSO" +.na +.nf +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 +.SH "README FILES" +.na +.nf +.ad +.fi +Use "\fBpostconf readme_directory\fR" or +"\fBpostconf html_directory\fR" to locate this information. +.na +.nf +SCHEDULER_README, scheduling algorithm +QSHAPE_README, Postfix queue analysis +.SH "LICENSE" +.na +.nf +.ad +.fi +The Secure Mailer license must be distributed with this software. +.SH "AUTHOR(S)" +.na +.nf +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 |