    DNSBLOG(8)                                                          DNSBLOG(8)

    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,  IP address, and an ID.  If
           the 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.  Otherwise it replies
           with the query  arguments  plus  an  empty  address  list.
           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 dns-
           blog(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, fil-
                  ters 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 direc-
                  tory.

           syslog_facility (mail)
                  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, "postfix/smtpd".

    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

                                                                        DNSBLOG(8)