Initially reported at EFForg/starttls-everywhere#146:
When I'm trying to submit my domain with an MTA STS policy at https://starttls-everywhere.org/add-domain/ I get the following error:
"Domain does not correctly implement MTA-STS."
The error comes from an API endpoint at https://starttls-everywhere.org/api/queue
I am not aware that anything is wrong with my MTA-STS setup. I also would strongly suggest to provide more meaningful error messages.