Ugly hack to download a couple of blocklist and use them in postfix

get-blocklist.sh

#!/bin/bash

# Go to our working directory
cd /tmp

# Download Blacklist
wget https://lists.blocklist.de/lists/all.txt --no-check-certificate
wget http://opendbl.net/lists/talos.list

# List cleaning
sed -i '1d' /tmp/talos.list

# Merge the blocklists
cat /tmp/talos.list >> /tmp/all.txt

# Make sure there are no duplicate IP's
sort all.txt | uniq > /tmp/iplist.tmp

# Add REJECT Your IP is spam
sed -i 's/$/\tREJECT Your IP is spam/g' /tmp/iplist.tmp

# Remove all IPv6 lines
grep -P "([0-9]{1,3}[\.]){3}[0-9]{1,3}" /tmp/iplist.tmp > /etc/postfix/client_checks

# Postmap convert
postmap -v /etc/postfix/client_checks

# Restart Postfix
service postfix restart

# Clean up temporary files
rm -f /tmp/all.txt /tmp/iplist.tmp /tmp/talos.list /tmp/all2.txt

Tested on postfix version 2.11.0