DKIM Check
Verify DKIM records for your domain and check email authentication status.
DKIM Configuration
Common Selectors
DKIM Record Status
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No DKIM result yet
WaitingPublic Key
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Record Parameters
Validation Results
DKIM Information
DKIM (DomainKeys Identified Mail) is an email authentication method that verifies an email was authorized by the domain owner and was not altered in transit.
Key Components
- • Signature in email headers
- • Public key in DNS
- • Private signing key
- • Selector (key version)
Benefits
- • Verifies sender authenticity
- • Improves email delivery
- • Prevents spoofing
- • Protects brand reputation
Learn more & FAQ
What does a DKIM checker do?
DKIM proves an email wasn't altered in transit by attaching a cryptographic signature that receiving servers verify against a public key published in your DNS. This tool looks up that DKIM record for your domain and selector, confirms it's correctly formatted and reachable, and shows you the public key it publishes.
How to read your results
Enter your domain and the selector your email provider gave you (often something like google or s1). A valid result shows the record found at that selector along with its key type and length. If nothing is found, double-check the selector and that the record has fully propagated since you published it.
Frequently asked questions
What is DKIM and what does it protect against?
DKIM (DomainKeys Identified Mail) attaches a cryptographic signature to outgoing email, generated from a private key your mail server holds. Receiving servers look up the matching public key in your DNS and verify the signature, confirming the message wasn't altered in transit and genuinely came from a server authorized to sign for your domain.
What is a DKIM selector?
A selector names which DKIM key a specific DNS record holds - it lets you run multiple DKIM keys at once (one per mail provider, for example) by publishing each one at its own selector._domainkey subdomain. You need to know your selector to check the right record.
Why does my DKIM check fail even though I set up DKIM with my email provider?
The most common cause is an incorrect or incomplete DNS record - a copy-paste error, a missing selector prefix, or the record not having propagated yet. Double-check the exact record your provider asked you to publish against what's actually live in DNS.
Do I need DKIM if I already have SPF set up?
Yes - SPF and DKIM check different things and most receiving mail servers (and DMARC) expect both. SPF authorizes which servers can send for your domain; DKIM verifies the message content wasn't tampered with. Together they give a much stronger signal than either alone.
How often should I rotate my DKIM keys?
Many providers recommend rotating DKIM keys roughly every 6-12 months as a general security hygiene practice, similar to rotating any other cryptographic key - though the exact cadence depends on your provider's own recommendation.