MTA-STS
Require sending systems to use authenticated TLS when delivering mail to you.
Live tool
Check policy
What is it?
MTA-STS combines a DNS TXT record with a policy file hosted at mta-sts.yourdomain.com.
Why is it important?
It helps prevent downgrade and man-in-the-middle attacks during inbound mail delivery.
How do you improve it?
Start in testing mode, validate the policy file, monitor TLS reports, and move to enforce mode.
How DomainShield Tower checks it
We inspect publicly available DNS, TLS, website, and reputation signals and explain the result in a report. Scanning is read-only and does not change your infrastructure.
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