Free tool
Email domain checker
See whether your domain is set up to send email that lands in the inbox: SPF, DKIM, DMARC and MX, explained in plain words with how to fix what is missing.
Free, no sign-up. Nothing is saved.
Questions, answered
What are SPF, DKIM and DMARC?
Three DNS records that prove your emails really come from you. SPF lists the services allowed to send as your domain, DKIM adds a signature to each email, and DMARC tells inboxes what to do with emails that fail those checks.
Do I need them?
Since 2024, Gmail and Yahoo require DKIM and DMARC from anyone who sends marketing email, and SPF or DKIM must line up with your domain. Without them, your emails are likely to land in spam or be rejected.
Why does it say no DKIM when I have it?
DKIM records live under a name each email service picks. We try the names popular services use, but yours may use another. Your email service shows the exact records it needs.
Is anything saved?
No. The checker reads your domain’s public DNS records and shows the result. Nothing is stored.
Step by step for SendDuo: Verify your sending domain. More free tools: Subject line tester.