grep tls main.cf:
smtpd_tls_key_file = /etc/postfix/ssl/example_com.key
smtpd_tls_cert_file = /etc/postfix/ssl/example_com.crt
smtpd_tls_CAfile = /etc/postfix/ssl/example_com.ca-bundle
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
smtp_use_tls = yes
#smtp_enforce_tls = yes
grep -A 4 smtps master.cf:
smtps inet n - - - - smtpd
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING