Check 6 of 54 · Email authentication

TLS reporting, explained.

Whether you are told when encrypted delivery to you fails.

Engine 1.57.0, read 25 October 2026

Free checkScoredReliability: Definitive

Can someone send email as you?

What the check does, and where it stops.

What it reads

The TXT record at _smtp._tls.yourdomain.

Why it matters

If a server cannot deliver to you securely, TLS reporting is how you find out. Without it, those failures are silent.

What a failure looks like

A failure is a finding in your result. The check is scored, so it can lower your score, and the Full Report gives every finding its severity and a fix. If the check cannot finish, it is recorded as unknown: it carries no penalty, and it is never a pass.

Where its limits are

Presence only, and more than one record counts as none.

ReliabilityDefinitive: reads a published value

Check 6 is one of 16 in Email authentication. See it in its row on the scanner page, beside the rest of Email authentication.

Run this check on any domain. Free, with no account.

The MTA-STS checker runs it on its own. It reads the policy that asks senders to deliver mail to you only over an encrypted connection, and your TLS reporting.

Open the MTA-STS checker

See how your domain does.

The free check includes this one and takes about 30 seconds. No account. Nothing to install.