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MTA-STS
Security
Email security mechanism allowing domains to publish policy requiring TLS for SMTP delivery and preventing downgrade attacks.
Definition
MTA-STS lets a domain publish a policy stating inbound mail must be delivered over TLS to approved MX hosts. It mitigates STARTTLS stripping/downgrade.
In plain English
Email security mechanism allowing domains to publish policy requiring TLS for SMTP delivery and preventing downgrade attacks.
Why this matters
Why it matters: Email often contains sensitive personal data; requiring TLS reduces interception risk in transit.
Example
Example: Deploy MTA-STS, keep policies updated, and monitor reports and delivery failures.