Free tool
DMARC checker.
Enter a domain to check its DMARC record, policy, and reporting configuration.
What is DMARC?
Domain-based Message Authentication tells receivers what to do with emails that fail SPF or DKIM checks.
Policy levels
none = monitor only. quarantine = send to spam. reject = bounce the email. Start with none, then escalate.
Why it matters
Without DMARC, anyone can spoof your domain. Receiving servers have no instruction on how to handle failures.