Tools

DKIM, SPF & DMARC Record Validator

Audit email deliverability records, SPF mechanisms, DMARC policies, DKIM selector keys, and MX routing.

Examples:

Why email authentication records determine your deliverability

Major inbox providers including Google, Yahoo, and Microsoft enforce strict email authentication policies. Without properly configured SPF, DKIM, and DMARC records, outbound business emails, transactional notifications, and marketing campaigns are frequently rejected or routed directly to the spam folder. This validator verifies record syntax, lookup limits, and alignment.

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Frequently Asked Questions

What are the Google and Yahoo 2024 sender requirements?

High-volume senders must have valid SPF and DKIM authentication, publish a DMARC policy with a valid reporting address, maintain spam rates below 0.3%, and support one-click unsubscribe headers.

What is the SPF 10-DNS-lookup limit?

RFC 7208 mandates that evaluating an SPF record must not cause more than 10 DNS lookups (e.g. from includes, mx, a, ptr mechanisms). Exceeding this limit causes a PermError and fails delivery.

What is the difference between DMARC p=none and p=reject?

Policy p=none is monitoring mode; unauthenticated messages are still delivered. Policy p=reject instructs receiving mail servers to discard unauthenticated emails completely, protecting your brand from impersonation.

How do I test my DKIM record if I have a custom selector?

Enter your domain and specify the selector name (e.g., google, k1, selector1) in the optional selector field. The tool checks the TXT record at <selector>._domainkey.<domain>.