DKIM Checker - Free Online IT Tool

🔑 DKIM Checker

Verify a domain's DomainKeys Identified Mail (DKIM) record using a selector.

ℹ️ About DKIM Checker

The DKIM Checker is a diagnostic tool used to retrieve and verify the public cryptographic key associated with a domain's email signature. DomainKeys Identified Mail (DKIM) adds a digital signature to every email you send. This signature allows the receiving server to verify that the email was indeed authorized by the owner of that domain and that the content has not been tampered with during transit.

Unlike SPF, DKIM requires a 'selector'—a specific string used to locate the public key in your DNS records. This allows organizations to use multiple keys for different services or departments. This tool helps you confirm that your public key is correctly published and accessible to external mail servers, which is essential for passing DMARC checks and maintaining high sender reputation.

📖 How to use DKIM Checker

1. Enter the domain name you are checking.
2. Enter the DKIM 'Selector.' You can find this in the headers of an email sent from your server (look for the <code>s=</code> tag in the <code>DKIM-Signature</code>).
3. Click 'Run Tool' to query the DNS for the public key.
4. Verify that the returned <code>p=</code> string matches the public key provided by your mail service.

❓ Frequently Asked Questions

What is a DKIM Selector?

A selector is a unique identifier used to distinguish between different DKIM keys. It is part of the DNS record path: <code>selector._domainkey.example.com</code>.