You should read: https://www.spamhaus.org/news/article/788/spamhaus-dnsbl-return-codes-technical-update.and https://docs.spamhaus.com/datasets/docs/source/40-real-world-usage/PublicMirrors/MTAs/020-Postfix.html
+1 and, https://www.google.com/search?q=spamhaus+postfix+zen -> first four links: Spamhaus Project Public Mirrors using Postfix https://docs.spamhaus.com/datasets/docs/source/40-real-world-usage/PublicMirrors/MTAs/020-Postfix.html Configuring DQS on Postfix https://docs.spamhaus.com/datasets/docs/source/40-real-world-usage/MTAs/020-Postfix.html ZEN - The Spamhaus Project https://www.spamhaus.org/zen/ DNSBL Usage FAQ - Spamhaus https://www.spamhaus.org/faq/section/DNSBL Usage
