TLS-RPT
SMTP TLS Reporting: a TXT record at _smtp._tls naming where sending servers should send daily reports of TLS connection successes and failures to a domain.
What it means
TLS-RPT (RFC 8460) gives a receiving domain visibility into TLS problems senders hit when delivering to it: certificate errors, missing STARTTLS, MTA-STS policy fetch failures or DANE validation errors. The domain publishes v=TLSRPTv1 with an rua= address, mailto: or https:, at _smtp._tls.
Participating senders send one JSON report per day, covering a full UTC day, summarizing successful and failed sessions with reasons.
It is the companion to MTA-STS and DANE: run MTA-STS in testing mode with TLS-RPT on, read the reports, and switch to enforce once failures stop.
Example
_smtp._tls.example.com. TXT "v=TLSRPTv1; rua=mailto:tls-reports@example.com"Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 8460: SMTP TLS Reportingrfc-editor.org
- RFC 8460: SMTP TLS Reporting, section 3rfc-editor.org
- RFC 8460: SMTP TLS Reporting, section 4.1rfc-editor.org
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