QMQPD(8)

NAME
qmqpd - Postfix QMQP server

SYNOPSIS
qmqpd [generic Postfix daemon options]

DESCRIPTION
The Postfix QMQP server receives one message per connection. Each message 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 authorized 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).

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 before 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
The following main.cf parameters are especially relevant to this program. See the Postfix main.cf file for syntax details and for default values. Use the postfix reload command after a configuration change.

Miscellaneous

debug_peer_level
    Increment in verbose logging level when a remote host matches a pattern in the debug_peer_list parameter.

debug_peer_list
    List of domain or network patterns. When a remote host matches a pattern, increase the verbose logging level by the amount specified in the debug_peer_level parameter.

hopcount_limit
    Limit the number of Received: message headers.

qmqpd_authorized_clients
    A list of domain or network patterns that specifies what clients are allowed to use the service.

qmqpd_timeout
    Limit the time to send a server response and to receive a client request.

soft_bounce
    Change hard (D) reject responses into soft (Z) reject responses. This can be useful for testing purposes.

Content inspection controls

content_filter
    The name of a mail delivery transport that filters mail and that either bounces mail or re-injects the result back into Postfix. This parameter uses the same syntax as the right-hand side of a Postfix transport table.

receive_override_options
    The following options override main.cf settings. The options are passed on to the downstream cleanup server.

    no_address_mappings
        Disable canonical address mapping, virtual alias map expansion, address masquerading, and automatic BCC recipients. Specify this if address mapping etc. are to be done after an external content filter.

    no_header_body_checks
        Disable header/body_checks. Specify this if header/body_checks are to be done after an external content filter.

Resource controls

line_length_limit
    Limit the amount of memory in bytes used for the handling of partial input lines, and the length of sender and recipient addresses that are received from client.

message_size_limit
    Limit the total size in bytes of a message, including on-disk storage for sender and recipient address information.

Tarpitting

qmqpd_error_delay
    Time to wait in seconds before informing the client of a problem. This slows down run-away errors.

SEE ALSO
http://cr.yp.to/proto/qmqp.html, QMQP protocol
cleanup(8) message canonicalization
master(8) process manager
syslogd(8) system logging

LICENSE
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