QMQPD(8)QMQPD(8)NAMEqmqpd - Postfix QMQP server
SYNOPSISqmqpd [generic Postfix daemon options]
The Postfix QMQP server receives one message per connection. Each mes‐
sage is piped through the cleanup(8) daemon, and is placed into the
incoming queue as one single queue file. The program expects to be run
from the master(8) process manager.
The QMQP server implements one access policy: only explicitly autho‐
rized client hosts are allowed to use the service.
The QMQP server is moderately security-sensitive. It talks to QMQP
clients and to DNS servers on the network. The QMQP server can be run
chrooted at fixed low privilege.
Problems and transactions are logged to syslogd(8).
The QMQP protocol provides only one server reply per message delivery.
It is therefore not possible to reject individual recipients.
The QMQP protocol requires the server to receive the entire message
before replying. If a message is malformed, or if any netstring compo‐
nent is longer than acceptable, Postfix replies immediately and closes
the connection. It is left up to the client to handle the situation.
Changes to main.cf are picked up automatically, as qmqpd(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.
CONTENT INSPECTION CONTROLS
After the message is queued, send the entire message to the
Enable or disable recipient validation, built-in content filter‐
ing, or address mapping.
RESOURCE AND RATE CONTROLS
Upon input, long lines are chopped up into pieces of at most
this length; upon delivery, long lines are reconstructed.
The maximal number of Received: message headers that is allowed
in the primary message headers.
The maximal size in bytes of a message, including envelope
The time limit for sending or receiving information over the
TROUBLE SHOOTING CONTROLS
The increment in verbose logging level when a remote client or
server matches a pattern in the debug_peer_list parameter.
Optional list of remote client or server hostname or network
address patterns that cause the verbose logging level to
increase by the amount specified in $debug_peer_level.
Safety net to keep mail queued that would otherwise be returned
to the sender.
How long the QMQP server will pause before sending a negative
reply to the client.
config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf con‐
How much time a Postfix daemon process may take to handle a
request before it is terminated by a built-in watchdog timer.
The time limit for sending or receiving information over an
internal communication channel.
The maximum amount of time that an idle Postfix daemon process
waits for an incoming connection before terminating voluntarily.
The maximal number of incoming connections that a Postfix daemon
process will service before terminating voluntarily.
The process ID of a Postfix command or daemon process.
The process name of a Postfix command or daemon process.
What clients are allowed to connect to the QMQP server port.
queue_directory (see 'postconf -d' output)
The location of the Postfix top-level queue directory.
The syslog facility of Postfix logging.
syslog_name (see 'postconf -d' output)
The mail system name that is prepended to the process name in
syslog records, so that "smtpd" becomes, for example, "post‐
The characters Postfix accepts as VERP delimiter characters on
the Postfix sendmail(1) command line and in SMTP commands.
Available in Postfix version 2.5 and later:
Enable logging of the remote QMQP client port in addition to the
hostname and IP address.
http://cr.yp.to/proto/qmqp.html, QMQP protocol
cleanup(8), message canonicalization
master(8), process manager
syslogd(8), system logging
Use "postconf readme_directory" or "postconf html_directory" to locate
QMQP_README, Postfix ezmlm-idx howto.
The Secure Mailer license must be distributed with this software.
The qmqpd service was introduced with Postfix version 1.1.
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA