How the DKIM check works
DKIM keys live at selector._domainkey.yourdomain.com, and the selector isn't public until you see a signed message. The check works out who hosts your email and tries the selectors that provider uses, selector1 and selector2 for Microsoft 365 and google for Google Workspace, plus selectors common email services use.
Every tool runs the same free check, which reads your MX, SPF, DKIM, DMARC, MTA-STS, website certificate, HTTPS, registration, DNSSEC and lookalike domains in one go.
Questions
- Why does the DKIM check say no key was found when I have DKIM?
- Your sender may use a selector we don't try. Check the DKIM-Signature header of a message you sent; the s= value is the selector.
See where your company stands
Check a domain for free, then connect Microsoft 365 or Google Workspace for the full checkup. Every new workspace gets a 7-day trial, no card needed.