Ein Nagios-Plugin von Heise, welches Mail-Server IP-Adressen gegen diverse DNS-Blacklisten prüft.

define command {
command_name check_dnsblk
command_line /usr/local/nagios/libexec/dnsbl-check-nagios.sh -H $HOSTADDRESS$
}

define service {
use generic-service
host_name mx.example.com
service_description dnsblk
display_name Mail DNS-Blacklist
check_command check_dnsblk
contact_groups Administratoren
}