/*++ /* NAME /* qmgr 8 /* SUMMARY /* old Postfix queue manager /* SYNOPSIS /* \fBqmgr\fR [generic Postfix daemon options] /* DESCRIPTION /* 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. /* MAIL QUEUES /* .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) agent 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. /* DELIVERY STATUS REPORTS /* .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. /* STRATEGIES /* .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. /* TRIGGERS /* .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. /* STANDARDS /* RFC 3463 (Enhanced status codes) /* RFC 3464 (Delivery status notifications) /* SECURITY /* .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. /* DIAGNOSTICS /* Problems and transactions are logged to the \fBsyslogd\fR(8) /* or \fBpostlogd\fR(8) daemon. /* 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. /* BUGS /* 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. /* CONFIGURATION PARAMETERS /* .ad /* .fi /* Changes to \fBmain.cf\fR are not picked up automatically, /* as \fBqmgr\fR(8) /* is a persistent process. Use the command "\fBpostfix reload\fR" 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. /* COMPATIBILITY CONTROLS /* .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 $default_filter_nexthop instead; when /* that value is empty, use the domain in the recipient address. /* ACTIVE QUEUE CONTROLS /* .ad /* .fi /* .IP "\fBqmgr_clog_warn_time (300s)\fR" /* The minimal delay between warnings that a specific destination is /* clogging up the Postfix active queue. /* .IP "\fBqmgr_message_active_limit (20000)\fR" /* The maximal number of messages in the active queue. /* .IP "\fBqmgr_message_recipient_limit (20000)\fR" /* The maximal number of recipients held in memory by the Postfix /* queue manager, and the maximal size of the short-term, /* in-memory "dead" destination status cache. /* DELIVERY CONCURRENCY CONTROLS /* .ad /* .fi /* .IP "\fBqmgr_fudge_factor (100)\fR" /* Obsolete feature: the percentage of delivery resources that a busy /* mail system will use up for delivery of a large mailing list /* message. /* .IP "\fBinitial_destination_concurrency (5)\fR" /* The initial per-destination concurrency level for parallel delivery /* to the same destination. /* .IP "\fBdefault_destination_concurrency_limit (20)\fR" /* The default maximal number of parallel deliveries to the same /* destination. /* .IP "\fBtransport_destination_concurrency_limit ($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. /* RECIPIENT SCHEDULING CONTROLS /* .ad /* .fi /* .IP "\fBdefault_destination_recipient_limit (50)\fR" /* The default maximal number of recipients per message delivery. /* .IP "\fBtransport_destination_recipient_limit ($default_destination_recipient_limit)\fR" /* A transport-specific override for the /* default_destination_recipient_limit parameter value, where /* \fItransport\fR is the master.cf name of the message delivery /* transport. /* OTHER RESOURCE AND RATE CONTROLS /* .ad /* .fi /* .IP "\fBminimal_backoff_time (300s)\fR" /* The minimal time between attempts to deliver a deferred message; /* prior to Postfix 2.4 the default value was 1000s. /* .IP "\fBmaximal_backoff_time (4000s)\fR" /* The maximal time between attempts to deliver a deferred message. /* .IP "\fBmaximal_queue_lifetime (5d)\fR" /* Consider a message as undeliverable, when delivery fails with a /* temporary error, and the time in the queue has reached the /* maximal_queue_lifetime limit. /* .IP "\fBqueue_run_delay (300s)\fR" /* The time between deferred queue scans by the queue manager; /* prior to Postfix 2.4 the default value was 1000s. /* .IP "\fBtransport_retry_time (60s)\fR" /* The time between attempts by the Postfix queue manager to contact /* a malfunctioning message delivery transport. /* .PP /* Available in Postfix version 2.1 and later: /* .IP "\fBbounce_queue_lifetime (5d)\fR" /* Consider a bounce message as undeliverable, when delivery fails /* with a temporary error, and the time in the queue has reached the /* bounce_queue_lifetime limit. /* .PP /* Available in Postfix version 2.5 and later: /* .IP "\fBdefault_destination_rate_delay (0s)\fR" /* The default amount of delay that is inserted between individual /* message deliveries to the same destination and over the same message /* delivery transport. /* .IP "\fBtransport_destination_rate_delay ($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. /* SAFETY CONTROLS /* .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. /* MISCELLANEOUS CONTROLS /* .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 /* 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.). /* 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 /* .ad /* .fi /* Use "\fBpostconf readme_directory\fR" or /* "\fBpostconf html_directory\fR" to locate this information. /* .na /* .nf /* QSHAPE_README, Postfix queue analysis /* LICENSE /* .ad /* .fi /* 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 /* /* Wietse Venema /* Google, Inc. /* 111 8th Avenue /* New York, NY 10011, USA
/*--*/
/* *Tunables.
*/ int var_queue_run_delay; int var_min_backoff_time; int var_max_backoff_time; int var_max_queue_time; int var_dsn_queue_time; int var_qmgr_active_limit; int var_qmgr_rcpt_limit; int var_init_dest_concurrency; int var_transport_retry_time; int var_dest_con_limit; int var_dest_rcpt_limit; char *var_defer_xports; int var_qmgr_fudge; int var_local_rcpt_lim; /* XXX */ int var_local_con_lim; /* XXX */ bool var_verp_bounce_off; int var_qmgr_clog_warn_time; char *var_conc_pos_feedback; char *var_conc_neg_feedback; int var_conc_cohort_limit; bool var_conc_feedback_debug; int var_xport_rate_delay; int var_dest_rate_delay; char *var_def_filter_nexthop; int var_qmgr_daemon_timeout; int var_qmgr_ipc_timeout; bool var_dsn_delay_cleared; int var_vrfy_pend_limit;
