MTA-STS policy is switched off
ATTENTIONWhat it means
mode: none tells senders to disregard any policy for example.com. It exists so you can withdraw a policy cleanly, leaving it there permanently means you have the DNS record, the file and the certificate, and none of the protection.
How to fix it
Set mode: testing while you validate, then mode: enforce.
Check your own domain
This page describes the condition. To find out whether your domain has it, run the MTASTS test or the full checkup, which examines every record at once.
Understand it properly
This page covers one condition. For the whole picture, MTA-STS, defined, or start at the Health Library.
Where this comes from
We judge this against RFC 8461 section 5. Every finding on this site cites the specification behind it so you can check the work rather than take our word for it.
Other MTASTS conditions
MTASTS_MODE_NONE
Every fix on this site is yours to implement. If you would rather someone did it, I take this work directly.