{ "content": [ { "type": "text", "text": "# QMGR (info)\n\n## NAME\n\nqmgr - Postfix queue manager\n\n## SYNOPSIS\n\nqmgr [generic Postfix daemon options]\n\n## DESCRIPTION\n\nThe qmgr(8) daemon awaits the arrival of incoming mail and arranges for\nits delivery via Postfix delivery processes. The actual mail routing\nstrategy is delegated to the trivial-rewrite(8) daemon. This program\nexpects to be run from the master(8) process manager.\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION**\n- **MAIL QUEUES**\n- **DELIVERY STATUS REPORTS**\n- **STRATEGIES**\n- **TRIGGERS**\n- **STANDARDS**\n- **SECURITY**\n- **DIAGNOSTICS**\n- **BUGS**\n- **CONFIGURATION PARAMETERS**\n- **COMPATIBILITY CONTROLS**\n- **ACTIVE QUEUE CONTROLS**\n- **DELIVERY CONCURRENCY CONTROLS**\n- **RECIPIENT SCHEDULING CONTROLS**\n- **MESSAGE SCHEDULING CONTROLS**\n- **OTHER RESOURCE AND RATE CONTROLS**\n- **SAFETY CONTROLS**\n- **MISCELLANEOUS CONTROLS**\n- **FILES**\n- **SEE ALSO**\n- **README FILES**\n- **LICENSE**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "QMGR", "section": "", "mode": "info", "summary": "qmgr - Postfix queue manager", "synopsis": "qmgr [generic Postfix daemon options]", "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [], "examples": [], "see_also": [ { "name": "trivial-rewrite", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/trivial-rewrite/8/json" }, { "name": "bounce", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/bounce/8/json" }, { "name": "postconf", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/postconf/5/json" }, { "name": "master", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/master/5/json" }, { "name": "master", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/master/8/json" }, { "name": "postlogd", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/postlogd/8/json" }, { "name": "syslogd", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/syslogd/8/json" } ], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 9, "subsections": [] }, { "name": "MAIL QUEUES", "lines": 21, "subsections": [] }, { "name": "DELIVERY STATUS REPORTS", "lines": 17, "subsections": [] }, { "name": "STRATEGIES", "lines": 39, "subsections": [] }, { "name": "TRIGGERS", "lines": 34, "subsections": [] }, { "name": "STANDARDS", "lines": 3, "subsections": [] }, { "name": "SECURITY", "lines": 6, "subsections": [] }, { "name": "DIAGNOSTICS", "lines": 7, "subsections": [] }, { "name": "BUGS", "lines": 4, "subsections": [] }, { "name": "CONFIGURATION PARAMETERS", "lines": 9, "subsections": [] }, { "name": "COMPATIBILITY CONTROLS", "lines": 13, "subsections": [] }, { "name": "ACTIVE QUEUE CONTROLS", "lines": 53, "subsections": [] }, { "name": "DELIVERY CONCURRENCY CONTROLS", "lines": 59, "subsections": [] }, { "name": "RECIPIENT SCHEDULING CONTROLS", "lines": 9, "subsections": [] }, { "name": "MESSAGE SCHEDULING CONTROLS", "lines": 36, "subsections": [] }, { "name": "OTHER RESOURCE AND RATE CONTROLS", "lines": 52, "subsections": [] }, { "name": "SAFETY CONTROLS", "lines": 14, "subsections": [] }, { "name": "MISCELLANEOUS CONTROLS", "lines": 49, "subsections": [] }, { "name": "FILES", "lines": 7, "subsections": [] }, { "name": "SEE ALSO", "lines": 8, "subsections": [] }, { "name": "README FILES", "lines": 5, "subsections": [] }, { "name": "LICENSE", "lines": 19, "subsections": [] } ], "sections": { "NAME": { "content": "qmgr - Postfix queue manager\n", "subsections": [] }, "SYNOPSIS": { "content": "qmgr [generic Postfix daemon options]\n", "subsections": [] }, "DESCRIPTION": { "content": "The qmgr(8) daemon awaits the arrival of incoming mail and arranges for\nits delivery via Postfix delivery processes. The actual mail routing\nstrategy is delegated to the trivial-rewrite(8) daemon. This program\nexpects to be run from the master(8) process manager.\n\nMail addressed to the local double-bounce address is logged and dis-\ncarded. This stops potential loops caused by undeliverable bounce no-\ntifications.\n", "subsections": [] }, "MAIL QUEUES": { "content": "The qmgr(8) daemon maintains the following queues:\n\nincoming\nInbound mail from the network, or mail picked up by the local\npickup(8) daemon from the maildrop directory.\n\nactive Messages that the queue manager has opened for delivery. Only a\nlimited number of messages is allowed to enter the active queue\n(leaky bucket strategy, for a fixed delivery rate).\n\ndeferred\nMail that could not be delivered upon the first attempt. The\nqueue manager implements exponential backoff by doubling the\ntime between delivery attempts.\n\ncorrupt\nUnreadable or damaged queue files are moved here for inspection.\n\nhold Messages that are kept \"on hold\" are kept here until someone\nsets them free.\n", "subsections": [] }, "DELIVERY STATUS REPORTS": { "content": "The qmgr(8) daemon keeps an eye on per-message delivery status reports\nin the following directories. Each status report file has the same name\nas the corresponding message file:\n\nbounce Per-recipient status information about why mail is bounced.\nThese files are maintained by the bounce(8) daemon.\n\ndefer Per-recipient status information about why mail is delayed.\nThese files are maintained by the defer(8) daemon.\n\ntrace Per-recipient status information as requested with the Postfix\n\"sendmail -v\" or \"sendmail -bv\" command. These files are main-\ntained by the trace(8) daemon.\n\nThe qmgr(8) daemon is responsible for asking the bounce(8), defer(8) or\ntrace(8) daemons to send delivery reports.\n", "subsections": [] }, "STRATEGIES": { "content": "The queue manager implements a variety of strategies for either opening\nqueue files (input) or for message delivery (output).\n\nleaky bucket\nThis strategy limits the number of messages in the active queue\nand prevents the queue manager from running out of memory under\nheavy load.\n\nfairness\nWhen the active queue has room, the queue manager takes one mes-\nsage from the incoming queue and one from the deferred queue.\nThis prevents a large mail backlog from blocking the delivery of\nnew mail.\n\nslow start\nThis strategy eliminates \"thundering herd\" problems by slowly\nadjusting the number of parallel deliveries to the same destina-\ntion.\n\nround robin\nThe queue manager sorts delivery requests by destination.\nRound-robin selection prevents one destination from dominating\ndeliveries to other destinations.\n\nexponential backoff\nMail that cannot be delivered upon the first attempt is de-\nferred. The time interval between delivery attempts is doubled\nafter each attempt.\n\ndestination status cache\nThe queue manager avoids unnecessary delivery attempts by main-\ntaining a short-term, in-memory list of unreachable destina-\ntions.\n\npreemptive message scheduling\nThe queue manager attempts to minimize the average per-recipient\ndelay while still preserving the correct per-message delays, us-\ning a sophisticated preemptive message scheduling.\n", "subsections": [] }, "TRIGGERS": { "content": "On an idle system, the queue manager waits for the arrival of trigger\nevents, or it waits for a timer to go off. A trigger is a one-byte mes-\nsage. Depending on the message received, the queue manager performs\none of the following actions (the message is followed by the symbolic\nconstant used internally by the software):\n\nD (QMGRREQSCANDEFERRED)\nStart a deferred queue scan. If a deferred queue scan is al-\nready in progress, that scan will be restarted as soon as it\nfinishes.\n\nI (QMGRREQSCANINCOMING)\nStart an incoming queue scan. If an incoming queue scan is al-\nready in progress, that scan will be restarted as soon as it\nfinishes.\n\nA (QMGRREQSCANALL)\nIgnore deferred queue file time stamps. The request affects the\nnext deferred queue scan.\n\nF (QMGRREQFLUSHDEAD)\nPurge all information about dead transports and destinations.\n\nW (TRIGGERREQWAKEUP)\nWakeup call, This is used by the master server to instantiate\nservers that should not go away forever. The action is to start\nan incoming queue scan.\n\nThe qmgr(8) daemon reads an entire buffer worth of triggers. Multiple\nidentical trigger requests are collapsed into one, and trigger requests\nare sorted so that A and F precede D and I. Thus, in order to force a\ndeferred queue run, one would request A F D; in order to notify the\nqueue manager of the arrival of new mail one would request I.\n", "subsections": [] }, "STANDARDS": { "content": "RFC 3463 (Enhanced status codes)\nRFC 3464 (Delivery status notifications)\n", "subsections": [] }, "SECURITY": { "content": "The qmgr(8) daemon is not security sensitive. It reads single-character\nmessages from untrusted local users, and thus may be susceptible to de-\nnial of service attacks. The qmgr(8) daemon does not talk to the out-\nside world, and it can be run at fixed low privilege in a chrooted en-\nvironment.\n", "subsections": [] }, "DIAGNOSTICS": { "content": "Problems and transactions are logged to syslogd(8) or postlogd(8).\nCorrupted message files are saved to the corrupt queue for further in-\nspection.\n\nDepending on the setting of the notifyclasses parameter, the postmas-\nter is notified of bounces and of other trouble.\n", "subsections": [] }, "BUGS": { "content": "A single queue manager process has to compete for disk access with mul-\ntiple front-end processes such as cleanup(8). A sudden burst of inbound\nmail can negatively impact outbound delivery rates.\n", "subsections": [] }, "CONFIGURATION PARAMETERS": { "content": "Changes to main.cf are not picked up automatically as qmgr(8) is a per-\nsistent process. Use the \"postfix reload\" command after a configuration\nchange.\n\nThe text below provides only a parameter summary. See postconf(5) for\nmore details including examples.\n\nIn the text below, transport is the first field in a master.cf entry.\n", "subsections": [] }, "COMPATIBILITY CONTROLS": { "content": "Available before Postfix version 2.5:\n\nallowminuser (no)\nAllow a sender or recipient address to have `-' as the first\ncharacter.\n\nAvailable with Postfix version 2.7 and later:\n\ndefaultfilternexthop (empty)\nWhen a contentfilter or FILTER request specifies no explicit\nnext-hop destination, use $defaultfilternexthop instead; when\nthat value is empty, use the domain in the recipient address.\n", "subsections": [] }, "ACTIVE QUEUE CONTROLS": { "content": "qmgrclogwarntime (300s)\nThe minimal delay between warnings that a specific destination\nis clogging up the Postfix active queue.\n\nqmgrmessageactivelimit (20000)\nThe maximal number of messages in the active queue.\n\nqmgrmessagerecipientlimit (20000)\nThe maximal number of recipients held in memory by the Postfix\nqueue manager, and the maximal size of the short-term, in-memory\n\"dead\" destination status cache.\n\nqmgrmessagerecipientminimum (10)\nThe minimal number of in-memory recipients for any message.\n\ndefaultrecipientlimit (20000)\nThe default per-transport upper limit on the number of in-memory\nrecipients.\n\ntransportrecipientlimit ($defaultrecipientlimit)\nA transport-specific override for the defaultrecipientlimit\nparameter value, where transport is the master.cf name of the\nmessage delivery transport.\n\ndefaultextrarecipientlimit (1000)\nThe default value for the extra per-transport limit imposed on\nthe number of in-memory recipients.\n\ntransportextrarecipientlimit ($defaultextrarecipientlimit)\nA transport-specific override for the defaultextrarecipi-\nentlimit parameter value, where transport is the master.cf name\nof the message delivery transport.\n\nAvailable in Postfix version 2.4 and later:\n\ndefaultrecipientrefilllimit (100)\nThe default per-transport limit on the number of recipients re-\nfilled at once.\n\ntransportrecipientrefilllimit ($defaultrecipientrefilllimit)\nA transport-specific override for the defaultrecipientre-\nfilllimit parameter value, where transport is the master.cf\nname of the message delivery transport.\n\ndefaultrecipientrefilldelay (5s)\nThe default per-transport maximum delay between recipients re-\nfills.\n\ntransportrecipientrefilldelay ($defaultrecipientrefilldelay)\nA transport-specific override for the defaultrecipientre-\nfilldelay parameter value, where transport is the master.cf\nname of the message delivery transport.\n", "subsections": [] }, "DELIVERY CONCURRENCY CONTROLS": { "content": "initialdestinationconcurrency (5)\nThe initial per-destination concurrency level for parallel de-\nlivery to the same destination.\n\ndefaultdestinationconcurrencylimit (20)\nThe default maximal number of parallel deliveries to the same\ndestination.\n\ntransportdestinationconcurrencylimit ($defaultdestinationconcur-\nrencylimit)\nA transport-specific override for the defaultdestinationcon-\ncurrencylimit parameter value, where transport is the master.cf\nname of the message delivery transport.\n\nAvailable in Postfix version 2.5 and later:\n\ntransportinitialdestinationconcurrency ($initialdestinationconcur-\nrency)\nA transport-specific override for the initialdestinationcon-\ncurrency parameter value, where transport is the master.cf name\nof the message delivery transport.\n\ndefaultdestinationconcurrencyfailedcohortlimit (1)\nHow many pseudo-cohorts must suffer connection or handshake\nfailure before a specific destination is considered unavailable\n(and further delivery is suspended).\n\ntransportdestinationconcurrencyfailedcohortlimit ($defaultdesti-\nnationconcurrencyfailedcohortlimit)\nA transport-specific override for the defaultdestinationcon-\ncurrencyfailedcohortlimit parameter value, where transport is\nthe master.cf name of the message delivery transport.\n\ndefaultdestinationconcurrencynegativefeedback (1)\nThe per-destination amount of delivery concurrency negative\nfeedback, after a delivery completes with a connection or hand-\nshake failure.\n\ntransportdestinationconcurrencynegativefeedback ($defaultdestina-\ntionconcurrencynegativefeedback)\nA transport-specific override for the defaultdestinationcon-\ncurrencynegativefeedback parameter value, where transport is\nthe master.cf name of the message delivery transport.\n\ndefaultdestinationconcurrencypositivefeedback (1)\nThe per-destination amount of delivery concurrency positive\nfeedback, after a delivery completes without connection or hand-\nshake failure.\n\ntransportdestinationconcurrencypositivefeedback ($defaultdestina-\ntionconcurrencypositivefeedback)\nA transport-specific override for the defaultdestinationcon-\ncurrencypositivefeedback parameter value, where transport is\nthe master.cf name of the message delivery transport.\n\ndestinationconcurrencyfeedbackdebug (no)\nMake the queue manager's feedback algorithm verbose for perfor-\nmance analysis purposes.\n", "subsections": [] }, "RECIPIENT SCHEDULING CONTROLS": { "content": "defaultdestinationrecipientlimit (50)\nThe default maximal number of recipients per message delivery.\n\ntransportdestinationrecipientlimit ($defaultdestinationrecipi-\nentlimit)\nA transport-specific override for the defaultdestinationrecip-\nientlimit parameter value, where transport is the master.cf\nname of the message delivery transport.\n", "subsections": [] }, "MESSAGE SCHEDULING CONTROLS": { "content": "defaultdeliveryslotcost (5)\nHow often the Postfix queue manager's scheduler is allowed to\npreempt delivery of one message with another.\n\ntransportdeliveryslotcost ($defaultdeliveryslotcost)\nA transport-specific override for the defaultdeliveryslotcost\nparameter value, where transport is the master.cf name of the\nmessage delivery transport.\n\ndefaultminimumdeliveryslots (3)\nHow many recipients a message must have in order to invoke the\nPostfix queue manager's scheduling algorithm at all.\n\ntransportminimumdeliveryslots ($defaultminimumdeliveryslots)\nA transport-specific override for the defaultminimumdeliv-\neryslots parameter value, where transport is the master.cf name\nof the message delivery transport.\n\ndefaultdeliveryslotdiscount (50)\nThe default value for transport-specific deliveryslotdiscount\nsettings.\n\ntransportdeliveryslotdiscount ($defaultdeliveryslotdiscount)\nA transport-specific override for the defaultdeliveryslotdis-\ncount parameter value, where transport is the master.cf name of\nthe message delivery transport.\n\ndefaultdeliveryslotloan (3)\nThe default value for transport-specific deliveryslotloan\nsettings.\n\ntransportdeliveryslotloan ($defaultdeliveryslotloan)\nA transport-specific override for the defaultdeliveryslotloan\nparameter value, where transport is the master.cf name of the\nmessage delivery transport.\n", "subsections": [] }, "OTHER RESOURCE AND RATE CONTROLS": { "content": "minimalbackofftime (300s)\nThe minimal time between attempts to deliver a deferred message;\nprior to Postfix 2.4 the default value was 1000s.\n\nmaximalbackofftime (4000s)\nThe maximal time between attempts to deliver a deferred message.\n\nmaximalqueuelifetime (5d)\nConsider a message as undeliverable, when delivery fails with a\ntemporary error, and the time in the queue has reached the maxi-\nmalqueuelifetime limit.\n\nqueuerundelay (300s)\nThe time between deferred queue scans by the queue manager;\nprior to Postfix 2.4 the default value was 1000s.\n\ntransportretrytime (60s)\nThe time between attempts by the Postfix queue manager to con-\ntact a malfunctioning message delivery transport.\n\nAvailable in Postfix version 2.1 and later:\n\nbouncequeuelifetime (5d)\nConsider a bounce message as undeliverable, when delivery fails\nwith a temporary error, and the time in the queue has reached\nthe bouncequeuelifetime limit.\n\nAvailable in Postfix version 2.5 and later:\n\ndefaultdestinationratedelay (0s)\nThe default amount of delay that is inserted between individual\nmessage deliveries to the same destination and over the same\nmessage delivery transport.\n\ntransportdestinationratedelay ($defaultdestinationratedelay)\nA transport-specific override for the defaultdestina-\ntionratedelay parameter value, where transport is the mas-\nter.cf name of the message delivery transport.\n\nAvailable in Postfix version 3.1 and later:\n\ndefaulttransportratedelay (0s)\nThe default amount of delay that is inserted between individual\nmessage deliveries over the same message delivery transport, re-\ngardless of destination.\n\ntransporttransportratedelay ($defaulttransportratedelay)\nA transport-specific override for the defaulttransportratede-\nlay parameter value, where the initial transport in the parame-\nter name is the master.cf name of the message delivery trans-\nport.\n", "subsections": [] }, "SAFETY CONTROLS": { "content": "qmgrdaemontimeout (1000s)\nHow much time a Postfix queue manager process may take to handle\na request before it is terminated by a built-in watchdog timer.\n\nqmgripctimeout (60s)\nThe time limit for the queue manager to send or receive informa-\ntion over an internal communication channel.\n\nAvailable in Postfix version 3.1 and later:\n\naddressverifypendingrequestlimit (see 'postconf -d' output)\nA safety limit that prevents address verification requests from\noverwhelming the Postfix queue.\n", "subsections": [] }, "MISCELLANEOUS CONTROLS": { "content": "configdirectory (see 'postconf -d' output)\nThe default location of the Postfix main.cf and master.cf con-\nfiguration files.\n\ndefertransports (empty)\nThe names of message delivery transports that should not deliver\nmail unless someone issues \"sendmail -q\" or equivalent.\n\ndelayloggingresolutionlimit (2)\nThe maximal number of digits after the decimal point when log-\nging sub-second delay values.\n\nhelpfulwarnings (yes)\nLog warnings about problematic configuration settings, and pro-\nvide helpful suggestions.\n\nprocessid (read-only)\nThe process ID of a Postfix command or daemon process.\n\nprocessname (read-only)\nThe process name of a Postfix command or daemon process.\n\nqueuedirectory (see 'postconf -d' output)\nThe location of the Postfix top-level queue directory.\n\nsyslogfacility (mail)\nThe syslog facility of Postfix logging.\n\nsyslogname (see 'postconf -d' output)\nA prefix that is prepended to the process name in syslog\nrecords, so that, for example, \"smtpd\" becomes \"prefix/smtpd\".\n\nAvailable in Postfix version 3.0 and later:\n\nconfirmdelaycleared (no)\nAfter sending a \"your message is delayed\" notification, inform\nthe sender when the delay clears up.\n\nAvailable in Postfix 3.3 and later:\n\nservicename (read-only)\nThe master.cf service name of a Postfix daemon process.\n\nAvailable in Postfix 3.5 and later:\n\ninfologaddressformat (external)\nThe email address form that will be used in non-debug logging\n(info, warning, etc.).\n", "subsections": [] }, "FILES": { "content": "/var/spool/postfix/incoming, incoming queue\n/var/spool/postfix/active, active queue\n/var/spool/postfix/deferred, deferred queue\n/var/spool/postfix/bounce, non-delivery status\n/var/spool/postfix/defer, non-delivery status\n/var/spool/postfix/trace, delivery status\n", "subsections": [] }, "SEE ALSO": { "content": "trivial-rewrite(8), address routing\nbounce(8), delivery status reports\npostconf(5), configuration parameters\nmaster(5), generic daemon options\nmaster(8), process manager\npostlogd(8), Postfix logging\nsyslogd(8), system logging\n", "subsections": [] }, "README FILES": { "content": "Use \"postconf readmedirectory\" or \"postconf htmldirectory\" to locate\nthis information.\nSCHEDULERREADME, scheduling algorithm\nQSHAPEREADME, Postfix queue analysis\n", "subsections": [] }, "LICENSE": { "content": "The Secure Mailer license must be distributed with this software.\n\nAUTHOR(S)\nWietse Venema\nIBM T.J. Watson Research\nP.O. Box 704\nYorktown Heights, NY 10598, USA\n\nPreemptive scheduler enhancements:\nPatrik Rak\nModra 6\n155 00, Prague, Czech Republic\n\nWietse Venema\nGoogle, Inc.\n111 8th Avenue\nNew York, NY 10011, USA\n\nQMGR(8postfix)", "subsections": [] } } } }