smtpd_banner = $myhostname ESMTP

disable_vrfy_command = yes
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, defer_unauth_destination

smtp_use_tls = yes
smtp_tls_CApath = /etc/ssl/certs
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt
smtp_tls_mandatory_protocols = !SSLv2,!SSLv3,!TLSv1,!TLSv1.1
smtp_tls_protocols = !SSLv2,!SSLv3,!TLSv1,!TLSv1.1
smtp_tls_security_level = may
smtp_tls_mandatory_ciphers = high