MTA-STS & TLS-RPT Checker
Free MTA-STS and TLS-RPT checker. Verify your inbound TLS enforcement and reporting records that protect email delivery from downgrade attacks. No login.
About the MTA-STS & TLS-RPT Checker
This free MTA-STS checker verifies the DNS records behind inbound TLS enforcement and TLS failure reporting for your domain. MTA-STS forces sending servers to deliver to you over verified, encrypted TLS - and refuse if they cannot - protecting your inbound mail from downgrade and interception attacks.
TLS-RPT is the companion record that has receivers report TLS delivery failures to you. Enter your domain to check both.
Frequently asked questions
What is MTA-STS?
MTA-STS (Mail Transfer Agent Strict Transport Security) tells sending servers they must deliver to your domain over verified TLS, and must not fall back to unencrypted delivery. It protects inbound mail from interception.
What is TLS-RPT?
TLS-RPT (TLS Reporting) is a TXT record telling receivers where to send reports when TLS delivery to your domain fails, so you learn about encryption problems you would otherwise miss.
Do I need MTA-STS?
Any business domain handling sensitive mail benefits from it. Most domains still do not have it, which makes it an easy trust and security differentiator.
Did this check reveal a problem?
Postbox Consultancy Services fixes email deliverability for a living - 500+ clients over 10+ years. Authentication, blacklist recovery, cold email infrastructure and full audits.