See what the public internet reports about your IP or domain: blocklist listings, reverse DNS and forward confirmation, and SPF/DMARC authentication posture — with a transparent public signal health score and exact weights.
Enter a public IP address for blocklist, PTR and FCrDNS checks — or a domain for blocklist and SPF/DMARC posture.
We query public DNS on your behalf: blocklist zones, PTR records, and SPF/DMARC TXT records. The address you enter is used only to run these lookups; results are not stored.
A public IP gets the IP pipeline: DNSBL blocklists, PTR reverse DNS, and forward-confirmed reverse DNS. A domain gets RHSBL domain blocklists plus SPF and DMARC posture. Private and reserved addresses are rejected — public blocklists do not cover them.
Each provider zone is queried through a bounded, time-capped run. A 127.0.0.0/8 answer is a listing with the provider’s documented meaning; no answer means not listed; a timeout or refusal stays unknown — never clean.
For a domain we list the infrastructure IPs it resolves to, but a website IP is not assumed to be your outbound sending IP. Only when you select an IP yourself do we run the sending-IP checks — and they are labeled as your selection.
Every factor, its weight, and its evidence are shown: 60/20/20 for IP inputs, 50/25/25 for domains, 50/15/15/10/10 with a selected sending IP. Unknown factors are excluded and the rest renormalized; any listing fails the check outright.
Deep-dive any IP or domain against every active DNSBL and RHSBL provider with per-provider delisting links.
Open toolVerify the SPF record behind your domain’s posture, including nested includes and the 10-lookup limit.
Open toolInspect the DMARC policy, reporting addresses, and external authorization that feed your domain score.
Open toolLook up and validate the DKIM key for your selector — the missing piece this score deliberately leaves out.
Open toolOnly what is publicly queryable: whether an IP appears in public DNS-based blocklists (DNSBLs), whether it has reverse DNS (PTR) that forward-confirms (FCrDNS), whether a domain appears in domain blocklists (RHSBLs), and the domain’s SPF and DMARC authentication posture. These are public signals — not the private reputation scores kept by Gmail, Microsoft, or other mailbox providers, which no external tool can query.
For an IP, the score is 100 points split across blocklists (60), PTR (20), and FCrDNS (20). For a domain, it is blocklists/RHSBL (50), SPF (25), and DMARC (25); when you also select a sending IP, the IP signals take the lead (blocklists 50, PTR 15, FCrDNS 15, SPF 10, DMARC 10). Each factor earns its full weight when healthy, zero when unhealthy, and is excluded — not counted as clean — when the lookup was inconclusive. Any conclusive blocklist listing fails the check regardless of the number. The score measures signal health, never deliverability or inbox placement.
A domain’s website IP (its A/AAAA record) is not necessarily the IP your mail is sent from — outbound mail often leaves through separate relay IPs. Pretending the website IP is the sending IP would produce a misleading verdict, so the tool lists the domain’s infrastructure IPs and only checks one as a “sending IP” when you explicitly identify it as such.
No. Unknown means the provider did not answer conclusively — typically a timeout or a refusal, since some operators block queries from public resolvers. Unknown results are excluded from the score and are never counted as clean or passing. Retry later or check the provider’s own lookup page.
No. A high public signal health score means your DNS signals look good, but inbox placement also depends on content, engagement, sending volume patterns, and the private reputation mailbox providers build from their own traffic. Treat this score as necessary hygiene, not a deliverability guarantee.
Looking up a DKIM record requires a selector name, which cannot be discovered reliably from DNS alone. Guessing common selectors produces false “missing DKIM” verdicts, so the score stays honest and leaves DKIM out — use the DKIM Record Checker with your selector instead.
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