@Drax, you can opt for below few mail filter option based on the spam mail header.
Who object (refer to Return-Path:)
- Email: email@example.com
- Domain: adoptionpatent.co
What object (subject)
- subject=(?i)(\W|^)(hope|pain|hidden secrets)(\W|$)
Maybe you can try all.spamrats.com as it contain all of it lists.
Apr 16 07:42:48 pmg postfix/dnsblog: addr 184.108.40.206 listed by domain bl.mailspike.net as 127.0.0.11
Apr 16 07:42:48 pmg postfix/dnsblog: addr 220.127.116.11 listed by domain...
Using zen.spamhaus.org*2,bl.mailspike.net,psbl.surriel.com,noptr.spamrats.com also having timeout with the spamrats DNSBL.
Maybe is their problem.
Apr 15 09:09:36 pmg postfix/postscreen: warning: dnsblog reply timeout 10s for noptr.spamrats.com
As far as I know there is no option to customize spamassain rule via GUI. Maybe you can request new feature to PMG's Dev.
Refer below link.