Glossary
TLS-RPT
A reporting mechanism and format by which sending systems share statistics and details of failed or downgraded TLS connections with the recipient domain.
In plain terms
The feedback channel that tells you when someone could not reach you securely.
Why it matters for deliverability
Without TLS-RPT, turning on MTA-STS enforcement is a blind change. With it, you can see certificate and connection failures before they start costing you mail.
What to do about it
- Publish a TLS-RPT record at the same time as MTA-STS, not after.
- Review reports for expired or mismatched certificates on any MX host.
- Keep watching after enforcement — certificates expire.
Source
“a reporting mechanism and format by which sending systems can share statistics and specific information about potential failures with recipient domains”
Checked 2026-08-29
Go deeper
Definitions reviewed 2026-08-29. Spotted something wrong? Tell us.
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