NAME

       filter-dnsbl — smtpd filter for DNSBL checks

SYNOPSIS

       filter-dnsbl [-h host]

DESCRIPTION

       filter-dnsbl  is  a  filter  for  smtpd(8) which can be used to check new connections against a DNS-based
       Blackhole List (DNSBL).

       The options are as follows:

       -h host  Set the DNSBL host to be queried.

                The default host is dnsbl.sorbs.net.

       The remote IP address of new connections is used in a DNS query against the DNSBL.  If the remote address
       is listed, the connection is rejected, otherwise accepted.

SEE ALSO

       filter_api(3), smtpd.conf(5), smtpd(8)

HISTORY

       The first version of filter-dnsbl was written in 2013.

AUTHORS

       Eric Faurot <eric@openbsd.org>

Debian                                            May 15, 2015                                   FILTER-DNSBL(8)