Email & DNS
DKIM Checker
Inspect DKIM public keys at a known selector or eight common selectors.
When to use this dkim checker
Check a published DKIM key after setting up email authentication or rotating a signing key. Enter the signing domain and optionally the selector from your provider or message headers.
What to look for
- Check a known selector using s= and d= from DKIM-Signature.
- Distinguish missing common selectors from a missing key your provider told you to publish.
- Review malformed or weak keys with the sending service before changing DNS.
How to read the results
Use s= and d= from a real message's DKIM-Signature header. A missing guessed selector does not mean DKIM is absent. This checks public keys, not message signatures or delivery.
PASS marks a stated check that passed. WARNING deserves review. FAIL marks a failed check. INFORMATION reports a fact. Results are a snapshot from our server, not a score or certification.
Does a key PASS prove my messages pass DKIM?
No. It shows that a public key can be read and parsed. Actual DKIM verification needs a message, its signature and its signed content. This checker does not send mail or verify signatures.
Download your results as Markdown to save the observations or discuss them with your AI assistant. Reports include the check timestamp and limitations.
DKIM selector not found: use the selector from a real message →