I managed today to use letsencrypt certificate for my mail-server as well. It was awesome easy.
i am using an ubuntu and have mail-server on the the same domain as my admin domain.
so – i got a letsencrypt certificate for this domain and used it as well for dovecot and postfix.
„Letsencrypt for Dovecot and Postfix“ weiterlesen
main.cf / postfix
smtpd_tls_cert_file = /etc/letsencrypt/live/y.jru.me/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/y.jru.me/privkey.pem