DKIM Checker

Verifies a domain’s DKIM (DomainKeys Identified Mail) record — the published public key that lets receivers confirm your messages were signed by you and not altered in transit.

Try it: sendlucid.com/dkim-checker

What you give it

A domain and a selector (defaults to default). The selector identifies which key to look up; your ESP assigns it (e.g. k1, s1, selector1). DKIM is published at {selector}._domainkey.{domain}.

What it checks

• A record exists at that selector.
• The version tag (v=DKIM1).
• A public key is present (p=) — an empty p= means the key is revoked.
• The key type (rsa or ed25519).

It returns the record, the parsed tags, and any issues.

Why it matters

DKIM is the second pillar of authentication, and it’s required for DMARC to pass by alignment. A missing or revoked key means your mail isn’t cryptographically signed.

How to read it

If you get “no record”, you likely have the wrong selector — check your ESP’s DKIM settings for the exact value. A present v=DKIM1 with a non-empty p= is a healthy key.