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MTA-STS

Security

Data in Transit TLS (Transport Layer Security) Phishing Email Forwarding

A way for email domains to require encrypted (TLS) email delivery.

Definition

MTA-STS helps mail servers know they should require TLS encryption when delivering email to a domain.

In plain English A way for email domains to require encrypted (TLS) email delivery.

Why this matters

Why it matters: It reduces the risk of attackers forcing email delivery over insecure connections.

Example

Example: A domain publishes an MTA-STS policy so mail servers use TLS.