DKIM Record Checker

How it works

DKIM signs each message with a private key. Receivers fetch the matching public key from DNS at <selector>._domainkey.<domain> and reject or distrust mail whose signature doesn't match.

We decode the key and report its real size. 1024-bit RSA keys still work but are below today's recommendation; anything shorter is rejected by major providers. An empty p= tag means the key was revoked.

Where do I find my selector? Open any email you sent, view the original message, and look for s= in the DKIM-Signature header.

Automate it with the API

Run this check for every address in your product, from any language.

curl -X POST "https://www.mailrambo.com/v1/verify?detail=full" \
  -H "Authorization: Bearer $MAILRAMBO_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email": "jane@acme.com"}'
# -> detail.dns: { spf, dmarc_policy, dkim_selectors, bimi, ptr, mx_hosts }

API reference · Get a free API key

Frequently asked questions