MTA-STS Studio is part of DNS Studio, a suite of focused, free tools for checking DNS, mail authentication, TLS, SSL and domain trust. Each tool does one job clearly, in plain language, with a Tech mode when you want the raw detail.
How it works
MTA-STS needs a DNS TXT record at _mta-sts.yourdomain and a policy file served over HTTPS at mta-sts.yourdomain/.well-known/mta-sts.txt. TLS-RPT adds a TXT record at _smtp._tls.yourdomain so senders can email you daily reports about TLS successes and failures.
Private by design
There are no accounts and no advertising trackers. The domain you check is used only to perform the lookup and show you the result. See our Privacy page for details.
The rest of the studio
Looking for something else? Try DNS Studio for records and propagation, DKIM, DMARC and BIMI for mail, or TLS and SSL for certificates. The full list is in the footer.
Contact
Feedback and corrections are welcome at [email protected].