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SPF & DMARC Checker — Validate Records Against the Real Spec

Paste your SPF and DMARC records and this tool validates them against the actual specification — mechanisms, the SPF 10-DNS-lookup limit that silently breaks authentication when exceeded, the dangerous "+all" catch-all, and DMARC policy and alignment settings — rather than just checking the records exist. AI then generates a corrected, copy-pasteable record for whatever it finds wrong.

How to use AI Email Deliverability Checker

  1. Paste your domain's SPF and DMARC records.
  2. Review the spec-level validation results.
  3. Check specifically for the 10-lookup limit and "+all" warnings.
  4. Copy the AI-corrected record into your DNS.

Frequently asked questions

What is the SPF 10-lookup limit?
SPF allows at most 10 DNS lookups when evaluating includes and redirects; exceeding it makes receiving servers treat the whole record as a permanent error, silently breaking authentication for legitimate mail.
Why is "+all" dangerous?
It tells receiving servers to pass any sender as authenticated, which defeats the purpose of SPF entirely and makes spoofing your domain trivial — "-all" or "~all" is what you actually want.
Does this check DKIM too?
This tool focuses on SPF and DMARC record validation. DKIM uses a separate per-selector DNS record and should be checked with your email provider's DKIM setup tool.

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