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 0x21.biz
Found
Selector: mail
(TXT on mail._domainkey.0x21.biz)
v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCvBtMieYv5xZgKHK+LHODGfB3XpWXT1QcM5+9ABAb5WbizkwklGI4P3g82YUQ4D/WxtReq9huRwDd5zjYlm3n0CXl5hNMW32w+35jm5cvxo06IdM3kdSYUmBRGa9hPiCtbnDsrlUdV028axA90B1vPKgiSx/dhmr+8i0JctErPjQIDAQAB
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.