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Free DNS and Email Authentication Tools

We’ve launched a set of free tools for diagnosing DNS, domain, and email delivery issues. These are the checks we run when troubleshooting delivery problems, and they’re now available to anyone with no account required.

  • Email Header Analyzer – trace a message’s delivery path and check its authentication results
  • MX Checker – find receiving mail servers and compare priorities
  • SPF Checker – validate a policy, inspect mechanisms, and count DNS lookups
  • DKIM Checker – validate a public key by domain and selector
  • DMARC Checker – review policy, alignment, and reporting addresses
  • SMTP TLS Checker – test STARTTLS support and certificate validity
  • PTR Checker – look up reverse DNS for an IPv4 or IPv6 address
  • DNS Checker – look up A, AAAA, CNAME, MX, TXT, NS, CAA, and SOA records
  • Nameserver Checker – find authoritative nameservers and identify the DNS provider
  • WHOIS/RDAP Checker – look up registration data, status, and DNSSEC

More tools will follow.

Explore the tools