Transport security

What is TLS-RPT?

How aggregate reports reveal failures in secure mail transport.

5 minute readUpdated October 16, 2026

Aggregate transport reporting

TLS-RPT lets a domain publish where participating senders should report TLS negotiation and policy failures.

Example

v=TLSRPTv1; rua=mailto:[email protected]

Pair it with transport policy

TLS-RPT is most useful alongside MTA-STS or DANE. Reports help find invalid certificates, MX mismatches and other delivery-path failures.