if header :contains "Subject" "SPAM"
{
fileinto "Junk";
stop;
}
iptables -I 1 DOCKER-USER -i eth0 -s your-network/24 -p tcp -m conntrack --ctorigdstport 27017 -j ACCEPT
iptables -I 2 DOCKER-USER -i eth0 -p tcp -m conntrack --ctorigdstport 27017 -j DROP