Free DKIM Record Checker
Validate your domain's DKIM configuration. We check common selectors for Google, Microsoft, and other major providers.
What Our Free DKIM Checker Tests
Common Selectors
Checks selectors used by Google, Microsoft, Amazon SES, Mailchimp, and more.
Key Strength
Validates key type (RSA/Ed25519) and key size to ensure adequate security.
Record Validation
Verifies DKIM record syntax and ensures the public key is properly formatted.
What is DKIM and How Does It Work?
DKIM (DomainKeys Identified Mail) is an email authentication method that adds a digital signature to your outgoing emails. Recipients can verify this signature to confirm the email wasn't modified in transit and truly came from your domain.
When you send an email, your mail server signs it using a private key. The recipient's server then retrieves your public key from DNS (the DKIM record) and verifies the signature.
Common DKIM Selectors by Provider
Google Workspace
googleMicrosoft 365
selector1, selector2Amazon SES
Various (check SES console)Mailchimp
k1Why DKIM Matters
DKIM is one of the three pillars of email authentication (along with SPF and DMARC). Without DKIM, your emails are more likely to be marked as spam, and you can't achieve a strict DMARC policy of "reject" safely.
Monitor Your DKIM Configuration
Get alerts when your DKIM keys expire or change. Our free tier includes continuous monitoring for SPF, DKIM, and DMARC.
DKIM FAQ
How do I set up DKIM for my domain?
DKIM setup depends on your email provider. For Google Workspace, go to Admin Console > Apps > Google Workspace > Gmail > Authenticate email. For Microsoft 365, use the Defender portal. Each provider will give you a CNAME or TXT record to add to your DNS.
What DKIM selector should I use?
Selectors are arbitrary strings chosen by your email provider. Common ones include 'google' for Google Workspace, 'selector1'/'selector2' for Microsoft 365, and 'k1' for Mailchimp. Your provider will specify which selector to use.
Why is my DKIM check showing 'Not Found'?
Either DKIM isn't configured for your domain, or we didn't check the right selector. DKIM records are stored at [selector]._domainkey.yourdomain.com. You may need to enable DKIM in your email provider's settings.
What key size should I use for DKIM?
Use at least 1024-bit RSA keys, though 2048-bit is recommended. Some providers now support Ed25519 keys which are smaller but equally secure. Avoid 512-bit keys as they can be cracked.