Free Tools

MTA-STS & TLS-RPT Checker

Check a domain

We fetch your policy the way sending mail servers do, and check it against your record and your mail servers.

What this checks

MTA-STS is three things that have to agree: a DNS record, a policy file served over HTTPS on its own subdomain, and the mail servers your MX records point at. When they disagree nothing tells you, and under enforce the disagreement is mail that does not arrive.

Enter a domain above. We check all three against each other, tell you which step of the rollout you are on, and give you the files for the next one.

Build a policy

Change anything and press Update. Building looks nothing up; with a domain filled in, it re-checks that domain.

Mode

One week is 604800. The RFC expects weeks or more.

Using Report URI? Your reporting address is on your Setup page. New here? Create a free account to get one.

Hear about failures the day they happen. Not the day someone asks where their email went.

Senders report every MTA-STS failure they meet, against every mail server, in a daily TLS-RPT report. Report URI collects them, shows which senders and servers fail and why, and keeps the history, so you know when enforce is safe and when it starts holding mail.

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