https://www.spamcop.net

https://www.dnsbl.info

http://www.barracudacentral.org

http://www.backscatterer.org

https://www.ahbl.org

https://www.abuseat.org

https://www.dan.me.uk/dnsbl

https://www.spamhaus.org/zen

http://www.sorbs.net

http://www.msrbl.com

https://www.megarbl.net

http://mailspike.org

http://filterdb.iss.net/dnsblinfo