DKIM Checker

Check DKIM record by selector. Validates key strength (1024 vs 2048 bits) and detects revoked keys.

Common selectors: default, google, k1, s1, selector1. Leave the field blank to probe the usual ones.

Senders such as SendGrid, Mailchimp and Amazon SES publish the key on their side and have you point the selector at it with a CNAME. To see where a selector points, run selector._domainkey.example.com through the CNAME Lookup; the raw TXT is in the TXT Lookup.