About DKIM Checker Tool
DKIM (DomainKeys Identified Mail) is an email authentication method that lets receiving mail servers verify that an email was actually sent by the domain it claims to be from, and that the message wasn’t altered in transit. When an email is sent, the sending server adds a digital signature to it. The receiving server then looks up the sender’s DKIM public key in DNS and uses it to verify that signature.
Use this tool to look up the DKIM record for any domain. Simply enter a domain name and the tool will automatically check for DKIM records across the most common selectors used by popular email providers including Google Workspace, Microsoft 365, Mailchimp, SendGrid, Mailjet, and more. If you know the specific selector for the domain, you can also look it up directly.
The results show the raw DKIM DNS record along with a plain-English breakdown of each field. This makes it easy to confirm that DKIM is correctly configured, identify which email provider is handling outbound mail for a domain, or troubleshoot email deliverability issues.
What you can check with this tool:
- Whether a domain has DKIM set up
- Which email service is sending mail on behalf of the domain
- The strength of the public key (e.g. 1024-bit vs 2048-bit)
- Whether a DKIM key has been revoked
- Whether the domain is in testing mode