MTA-STS?
"Google has deployed MTA-STS, and past experience suggests that this means, "Here's some totally useless new thing, but if you don't implement it, we're eventually going to stop accepting your email." So can someone point me at simple instructions to make it go on my mail server? (Postfix 2.10, Centos 7, certs via Letsencrypt) Or tell me that this is a thing that nobody will ever care about. ..."