SSL/TLS in Postfix and Dovecot: why and how
Let's Encrypt certificate, ports 465/587/993/995, TLS 1.2 where there is a password, Dovecot 2.3 and 2.4, tests, and MTA-STS against the attack that strips STARTTLS.
certbot
Let's Encrypt certificate, ports 465/587/993/995, TLS 1.2 where there is a password, Dovecot 2.3 and 2.4, tests, and MTA-STS against the attack that strips STARTTLS.