KMMR Online Tools

Mail DNS Authentication Checker

Check SPF, DMARC, and DKIM public keys for a domain in one place. Review published records, policy mode, key size, and common setup issues.

Need to confirm TXT propagation too?

If you want to compare public resolver answers and propagation status, open DNS Lookup & Propagation Checker

Enter multiple selectors separated by commas or new lines. If left blank, the tool tries common selector candidates automatically.

What is a selector?

DKIM public keys are published under names like selector._domainkey.example.com. The selector differs by sending service, and values such as default or selector1 are common.

The exact value can usually be found in the s= field of the DKIM-Signature header or in your mail provider admin screen.

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