CaptainDNS

What it does

CaptainDNS lets you diagnose DNS zones and audit email security records, SPF, DKIM, DMARC, MTA-STS, BIMI and DNSSEC, for free. Unlike basic DNS checkers, it covers the full resolution chain across 18 resolvers on 4 continents. Already used to analyse 48K+ domains, it gives developers and IT teams actionable diagnostics in one place, without switching between multiple tools.

Audit SPF, DKIM, DMARC, MTA-STS, BIMI and DNSSEC for free. 48K+ domains analyzed, 18 resolvers across 4 continents, results in seconds.

Domain, IP, email, URL or raw DNS record. We detect the input and run the right audit in under 3 seconds. 1.5M+ domains audited this month · 7 protocols checked in parallel · under 3s p95 For the parts of your stack that need uptime, alerts and a real owner, not a one-off check. Real-time rua/ruf reports, sender breakdowns and alerts when alignment breaks. Continuous monitoring of your email security and deliverability. Get alerted whenever a score or DNS record changes enough to affect deliverability or security. Multi-region uptime checks, 3-region consensus, alerts. Security score: SSL/TLS, HSTS, headers, phishing. Public status pages tied to your monitors. Custom domain, incidents,…from captaindns.com

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