QMQPD(8) System Manager's Manual QMQPD(8)
NAME
qmqpd - Postfix QMQP server
SYNOPSIS
qmqpd [generic Postfix daemon options]
DESCRIPTION
The Postfix QMQP server receives one message per connection. Each mes‐
sage is piped through the cleanup(8) daemon, and is placed into the in‐
coming 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.
SECURITY
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.
DIAGNOSTICS
Problems and transactions are logged to syslogd(8) or postlogd(8).
BUGS
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 be‐
fore replying. If a message is malformed, or if any netstring component
is longer than acceptable, Postfix replies immediately and closes the
connection. It is left up to the client to handle the situation.
CONFIGURATION PARAMETERS
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
content_filter (empty)
After the message is queued, send the entire message to the
specified transport:destination.
receive_override_options (empty)
Enable or disable recipient validation, built-in content filter‐
ing, or address mapping.
SMTPUTF8 CONTROLS
Preliminary SMTPUTF8 support is introduced with Postfix 3.0.
smtputf8_enable (yes)
Enable preliminary SMTPUTF8 support for the protocols described
in RFC 6531, RFC 6532, and RFC 6533.
smtputf8_autodetect_classes (sendmail, verify)
Detect that a message requires SMTPUTF8 support for the speci‐
fied mail origin classes.
Available in Postfix version 3.2 and later:
enable_idna2003_compatibility (no)
Enable 'transitional' compatibility between IDNA2003 and
IDNA2008, when converting UTF-8 domain names to/from the ASCII
form that is used for DNS lookups.
RESOURCE AND RATE CONTROLS
line_length_limit (2048)
Upon input, long lines are chopped up into pieces of at most
this length; upon delivery, long lines are reconstructed.
hopcount_limit (50)
The maximal number of Received: message headers that is allowed
in the primary message headers.
message_size_limit (10240000)
The maximal size in bytes of a message, including envelope in‐
formation.
qmqpd_timeout (300s)
The time limit for sending or receiving information over the
network.
TROUBLE SHOOTING CONTROLS
debug_peer_level (2)
The increment in verbose logging level when a nexthop destina‐
tion, remote client or server name or network address matches a
pattern given with the debug_peer_list parameter.
debug_peer_list (empty)
Optional list of nexthop destination, remote client or server
name or network address patterns that, if matched, cause the
verbose logging level to increase by the amount specified in
$debug_peer_level.
soft_bounce (no)
Safety net to keep mail queued that would otherwise be returned
to the sender.
TARPIT CONTROLS
qmqpd_error_delay (1s)
How long the Postfix QMQP server will pause before sending a
negative reply to the remote QMQP client.
MISCELLANEOUS CONTROLS
config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf con‐
figuration files.
daemon_timeout (18000s)
How much time a Postfix daemon process may take to handle a re‐
quest before it is terminated by a built-in watchdog timer.
ipc_timeout (3600s)
The time limit for sending or receiving information over an in‐
ternal communication channel.
max_idle (100s)
The maximum amount of time that an idle Postfix daemon process
waits for an incoming connection before terminating voluntarily.
max_use (100)
The maximal number of incoming connections that a Postfix daemon
process will service before terminating voluntarily.
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.
qmqpd_authorized_clients (empty)
What remote QMQP clients are allowed to connect to the Postfix
QMQP server port.
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".
verp_delimiter_filter (-=+)
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:
qmqpd_client_port_logging (no)
Enable logging of the remote QMQP client port in addition to the
hostname and IP address.
Available in Postfix 3.3 and later:
service_name (read-only)
The master.cf service name of a Postfix daemon process.
SEE ALSO
https://cr.yp.to/proto/qmqp.html, QMQP protocol
cleanup(8), message canonicalization
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
README FILES
QMQP_README, Postfix ezmlm-idx howto.
LICENSE
The Secure Mailer license must be distributed with this software.
HISTORY
The qmqpd service was introduced with Postfix version 1.1.
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
QMQPD(8)