Comment 26 for bug 1881196

Bionic verification:

$ lxc launch ubuntu-daily:bionic postfix-cert
$ lxc shell postfix-cert
# apt-get update && apt-get upgrade -y
# cat <<EOF >/etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe
EOF
# apt-get update && apt-get install -y postfix/bionic-proposed
# postfix tls deploy-server-cert /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/private/ssl-cert-snakeoil.key
postfix/postfix-tls-script: New TLS private key and certificate deployed.
postfix/postfix-tls-script: Run the command:
postfix/postfix-tls-script: # postfix reload
postfix/postfix-tls-script: if you want the new settings to take effect immediately.