TLS-RPT gives a receiving domain visibility into TLS problems observed by participating sending systems.
A policy is published under _smtp._tls:
_smtp._tls.example.com. IN TXT "v=TLSRPTv1; rua=mailto:tls-reports@example.com"Reports can expose certificate validation failures, policy mismatches and TLS negotiation problems that would otherwise only appear in another organization’s outbound logs.
TLS-RPT is reporting. It does not itself force TLS. Enforcement can come from mechanisms such as MTA-STS or DANE.