Provided by: opensmtpd-extras_5.7.1-1build1_amd64
filter-dnsbl — smtpd filter for DNSBL checks
filter-dnsbl [-h host]
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.
filter_api(3), smtpd.conf(5), smtpd(8)
The first version of filter-dnsbl was written in 2013.
Eric Faurot <email@example.com>