DKIM Checker

Check whether your domain has a valid DKIM record. DKIM signs your outgoing mail so receivers can confirm it really came from you and wasn't altered.

Want the full picture - MX, SPF, DKIM, DMARC and more?

Run a full Domain Check
DKIM selector (optional)

We probe common selectors automatically. Enter your own if you know it (it's the s= tag in a message's DKIM-Signature header).

About these results

This tool reads your domain's public DKIM (TXT) records at the moment of the check. DKIM records live under a selector that is unique to each provider, so we probe common selectors and any selector you enter - a "not found" result does not always mean DKIM is missing. Results reflect current public DNS and can be affected by caching and propagation (up to 24-48 hours). Guidance is general and not a substitute for your provider's official instructions. We don't store the domains you check.

What is DKIM?

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to every message you send. Your provider signs with a private key and publishes the matching public key in DNS. Receivers verify the signature - proving the message really came from your domain and wasn't changed in transit.

How DKIM works

The public key lives at <selector>._domainkey.yourdomain. The selector is chosen by your provider, so a DKIM record can't be discovered without it.

Common problems and fixes

Related checks: Full domain check SPF DMARC MX lookup MTA-STS TLS-RPT DNSSEC BIMI