DKIM Test — Check your records instantly
Free DKIM checker and validator. Verify your DKIM keys, test selectors, and monitor for changes that could break email authentication.
Having trouble finding the right selector? Learn how to find yours.
What is DKIM?
DKIM (DomainKeys Identified Mail) adds a cryptographic signature to your outgoing emails. The sending server signs each message with a private key, and publishes the matching public key in DNS. When the receiving server gets your email, it uses the public key to verify the signature — proving the message came from you and wasn't altered in transit.
DKIM records are published under a selector, like `selector1._domainkey.example.com`. Most email services use their own selectors, so a single domain often has multiple DKIM keys — one for Google Workspace, another for Mailchimp, another for SendGrid, and so on. If any key is missing, expired, or misconfigured, emails from that service fail DKIM verification.
Our free DKIM tester checks any selector and domain combination instantly. Enter your domain and selector to verify your key is published, correctly formatted, and ready for signing.
Everything you need to monitor email deliverability
Monitor SPF records for changes and DNS lookup limit issues.
Monitor DKIM keys for changes and validity.
Monitor DMARC policy for changes affecting failed email handling.
Monitor MX records for changes that could break inbound email.
Monitor BIMI record and logo URL for brand display issues.
Check major blacklists daily for your domain and sending IPs.
Free Checker. Free Monitoring. Paid Unlimited.
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DKIM Record Checker
- Record changes
- Key presence
- Key validity
- Selector configuration
Email Deliverability
- Up to 3 domains
- Daily checks
- SPF, DKIM, DMARC, BIMI, MX monitoring
- Blacklist monitoring
- Email alerts
Email Deliverability Pro
- Unlimited domains
- Up to 5 co-recipients
- Custom check timing
- On-demand manual checks
- Bulk CSV import
Start monitoring your email deliverability
Get alerted before authentication issues affect your emails.