DKIM Record Checker

DKIM signs outgoing emails. Receivers verify the signature using a public key in DNS.

DKIM lives on <selector>._domainkey.<domain>. If selector is empty, we try common ones.

Result for hatena.ne.jp

Found
Selector: google (TXT on google._domainkey.hatena.ne.jp)
v=DKIM1; k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsDrUo+9l0jnOZPnxGbsIwE92MA7Rb7oP8UsCEJBSuzHku/hxBvpkZ3WxO8YRydpqSA+WJgQZRrDdinMIlw/k0iuQrVI5/MKfLrpavPszojdRdd7RlHy0BG9iHlXtv4SAi0LqBt8tYB6ds/eAHJrzwxR9TitGTc4DcLsNahF0fUwI3iaTouz+eTiK+lAsOSei9IZkc+y86zqbLHbt2zm3xR2FAr3d+neIIwJSYD2LHv+FhQcyTz7pQT90MLL3ymV7SGOGSrlTOl/eKBuT23lWHztVMWJgat71O0InD6ATA+xTk4VRE8XlwR0wOamNtB2mC5ivM5G0zxq+KJJ/GuWeJwIDAQAB

FAQ

Why does DKIM require a selector?
Selectors allow rotating keys and running multiple keys per domain.
Where is DKIM published?
TXT on <selector>._domainkey.<domain>.
DKIM record exists but emails still fail DKIM?
Signing may be disabled or the selector used in email differs from DNS.
Do I need DKIM if I have SPF?
Yes, many providers use both for best deliverability and DMARC alignment.
Can I have multiple DKIM selectors?
Yes, that is common for key rotation or multiple senders.

What is DKIM?

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outgoing emails. DNS stores a public key that allows receivers to verify authenticity.

Example

v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0B...

Common mistakes

  • Wrong selector (the record exists but under a different selector).
  • Key is split incorrectly across multiple TXT chunks (some DNS UIs break it).
  • Publishing DKIM but not enabling signing on the mail provider.