Domain checker
Seven protocols in one run: DMARC, SPF, DKIM, MX, MTA-STS, BIMI and DNSSEC. The same checks the monitoring product runs, on the same code. Free, without an account, and without storing what you type.
No account, no e-mail, nothing stored. The checks run against public DNS and are the same ones the monitoring product uses. Fair-use limit: 15 checks a minute.
What each result means
A pass means the record is published and reads the way the specification says it should. It is not a promise that your mail authenticates everywhere, because that depends on who sends on your behalf, which is what the aggregate reports answer and a one-off lookup cannot.
Attention means the record exists and something in it will cost you later, for example a policy still in monitoring mode, a lookup budget close to the RFC 7208 limit, or a selector that no longer resolves.
Problem means the record is missing or malformed. A domain with no DMARC record is not an error on our side; the checker says so in those words.
Start with the domain you worry about most
We built these checks for our own mail and run them against our own domains every day. The free plan covers one domain and needs no card.