NAME

       dnsblog - Postfix DNS white/blacklist logger

SYNOPSIS

       dnsblog [generic Postfix daemon options]

DESCRIPTION

       The  dnsblog(8)  server  implements  an ad-hoc DNS white/blacklist lookup service. This may eventually be
       replaced by an UDP client that is built directly into the postscreen(8) server.

PROTOCOL

       With each connection, the dnsblog(8) server receives a DNS white/blacklist domain name,  an  IP  address,
       and  an  ID.   If  the IP address is listed under the DNS white/blacklist, the dnsblog(8) server logs the
       match and replies with the query arguments  plus  an  address  list  with  the  resulting  IP  addresses,
       separated  by whitespace, and the reply TTL.  Otherwise it replies with the query arguments plus an empty
       address list and the reply TTL; the reply TTL is -1 if there is  no  reply,  or  a  negative  reply  that
       contains no SOA record.  Finally, the dnsblog(8) server closes the connection.

DIAGNOSTICS

       Problems and transactions are logged to syslogd(8).

CONFIGURATION PARAMETERS

       Changes  to main.cf are picked up automatically, as dnsblog(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.

       config_directory (see 'postconf -d' output)
              The default location of the Postfix main.cf and master.cf configuration files.

       daemon_timeout (18000s)
              How much time a Postfix daemon process may take to handle a request before it is terminated  by  a
              built-in watchdog timer.

       postscreen_dnsbl_sites (empty)
              Optional list of DNS white/blacklist domains, filters and weight factors.

       ipc_timeout (3600s)
              The time limit for sending or receiving information over an internal communication channel.

       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.

       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".

       Available in Postfix 3.3 and later:

       service_name (read-only)
              The master.cf service name of a Postfix daemon process.

SEE ALSO

       smtpd(8), Postfix SMTP server
       postconf(5), configuration parameters
       syslogd(5), system logging

LICENSE

       The Secure Mailer license must be distributed with this software.

HISTORY

       This service was introduced with Postfix version 2.8.

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

                                                                                               DNSBLOG(8postfix)