What is

What is TLS-RPT

TLS-RPT is a TXT record at _smtp._tls. It tells sending mail servers where to send reports about TLS failures on the way in.

_smtp._tls.example.com. IN TXT "v=TLSRPTv1;rua=mailto:[email protected]"

Records that do not begin with v=TLSRPTv1; are discarded. rua can be a mailto URI or an HTTPS URI. The TXT line above is the MAILTO example in RFC 8460.