Matej

How about jitsi? https://github.com/jitsi/docker-jitsi-meet I am running it for years, works much better than Facebook Messenger that is for sure 😃 not sure what you mean about the “all the standards”

Btw, I do not use postfix

if you use starttls, just use tls_type: "starttls" in your config

My instance had the same problem, the problem was that Hetzner (where I host my server) by default is not permitting outbound smtp ports. For me the solution was to use alternative port and even that a starttls alternative port which AWS SES luckily supports (that is what I am using for smtp server). Alternative would be also to just ask Hetzner to unblock the port (people have reported success with this method).