Blacklists: the twenty lists that actually decide your deliverability
DNS blocklists are operator-run databases of IPs seen sending spam. Land on the wrong one and major receivers refuse your mail before content is even evaluated.
More is not better: tools that query 100 zones mostly surface dead lists and pay-to-delist traps. Our list is curated — the zones receivers actually query — and every verdict links the zone's own delisting procedure.
Run it on your domain — the audit includes this check.
Other tools: SPF · DMARC · llms.txt · Header analyzer