DKIM Checker

Check a domain's DKIM record for a specific selector.

DKIM selectors aren't discoverable automatically — check your email provider's setup documentation, or a recent email's headers, for the exact selector name.

About this tool

DKIM (DomainKeys Identified Mail) lets a receiving mail server cryptographically verify that a message genuinely came from the domain it claims and wasn't altered in transit. Unlike SPF and DMARC, a DKIM record lives at a selector-specific location (selector._domainkey.domain.com) — there's no single fixed place to look it up, which is why this tool asks for both the domain and the selector.

Finding your selector

Your email provider's setup documentation usually names it explicitly (Google Workspace commonly uses "google", for example). It's also visible in the DKIM-Signature header of any email actually sent from your domain, in the s= field.

Related tools:

SPF Checker DMARC Checker Email Security Checker