CertaDNS

Free tools

Find out what your domain is actually publishing

Every tool here reads public DNS, shows you the raw record, and explains what it means. No account, no email address, and no result held back behind a signup.

Domain Trust Scanner

Start here

Thirty checks across DNS, email authentication and mail transport, with a score you can reproduce.

Is my domain set up to be trusted — and what should I fix first?

Check my domain

Can someone else send mail as my domain?

SPF Inspector · DKIM Inspector · DMARC Inspector

Is mail to my domain encrypted in transit?

MTA-STS Checker

Can a resolver tell my answers from forged ones?

DNSSEC Analyzer

Why is my logo not showing in the inbox?

BIMI Checker

What these tools can and cannot tell you

Every check reads what is published in public DNS, plus — for MTA-STS and BIMI — the public HTTPS resource the record points at. That is enough to catch the large majority of real misconfigurations, because most of them are visible from outside.

It is not enough to tell you whether your mail is actually being delivered. A domain can publish a flawless SPF, DKIM and DMARC set and still have a sending service that is not aligned, or a forwarding path that breaks alignment after the fact. Only aggregate DMARC reports show you that, because only the receiving mailbox providers can see it.

We also cannot enumerate your DKIM selectors. DNS has no way to list what exists under a name, so any DKIM check — ours or anyone else's — is either guessing from a list of common selectors or being told which one to look at. The DKIM Inspector lets you supply yours, and says which results came from a guess.

Found something you want fixed for good?

Every tool links to the manual fix first. If you would rather not maintain it by hand, that is what the products are for — and the prices are published.