[ Free tool · Email Authentication ]

DKIM Lookup

Verify a DKIM selector is published and the key is valid.

Leave the selector blank to try 20 common ones (google, selector1, k1, s1…).

[ About this tool ]

This DKIM lookup fetches the public key at <selector>._domainkey.<domain>, decodes it and reports the key type and length.

How to read the results

  • ›2048-bit RSA or Ed25519 keys are recommended.
  • ›1024-bit keys still work but are weak.
  • ›An empty p= value means the key was revoked.
  • ›Find the selector in the s= tag of a message's DKIM-Signature header.

Frequently asked questions

How do I find my DKIM selector?

Open a sent message's original headers and look for s= in the DKIM-Signature line. Common selectors include google, selector1, selector2, k1 and s1.

How do I test DKIM?

Look up the selector here, then send a message to yourself and check the Authentication-Results header for dkim=pass.

Learn more in our guide: DKIM (DomainKeys Identified Mail)

Enterprise provenance

Why top financial institutions and governments retired their email security dashboards.

Traditional email authentication platforms sell you a dashboard and ask your engineers to do the labour. In high-stakes environments, manual oversight means delayed enforcement, configuration drift and unmonitored shadow domains.

EmailAuth is the agentic email provenance platform. Our agents enforce p=reject, keep third-party senders aligned and move your domains to full RFC 9989 compliance, the new DMARC standard,, with human-in-the-loop auditability.

Governments Large enterprises Tier-1 financial institutions

SaaS · Dedicated tenancy · Air-gapped on-prem · BYOK encryption

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