DKIM Checker
A DKIM checker verifies the public key your domain publishes so receivers can confirm your mail is genuinely signed. This free tool auto-probes the common selectors (google, selector1/2, k1 and more) — or looks up a selector you enter — and shows which ones are live.
Auto-probes google · default · selector1/2 · k1/k2 · s1/s2 · mail · dkim · smtp
Frequently asked questions
What is a DKIM record?
DKIM (DomainKeys Identified Mail) publishes a public key in DNS at selector._domainkey.yourdomain. Your mail server signs outgoing messages with the matching private key so receivers can verify the message really came from you and was not altered.
How do I find my DKIM selector?
The selector is the label before ._domainkey in the DNS record, chosen by your mail provider — e.g. google (Google Workspace), selector1/selector2 (Microsoft 365), k1 (Mailchimp). This tool auto-probes the common ones; if yours is custom, type it in the selector box.
Why can't you find my DKIM record?
DKIM records only exist at specific selectors, and there is no way to list them from DNS — you can only look one up if you know its name. If auto-probing misses yours, enter your selector. A "not found" result is inconclusive, not proof DKIM is broken.
How many DKIM keys should I have?
At least one active key per sending service. Many providers publish two (selector1/selector2 or s1/s2) to allow key rotation without downtime. Use 2048-bit keys where supported.
Does DKIM stop spoofing on its own?
No. DKIM proves a message was signed by your domain, but only DMARC ties SPF/DKIM results to the visible From address and tells receivers to reject failures. Run all three together.