Enabling TLS in Postifx. Here are the needed lines to enable TLS within Postfix, this works on any of the modern Redhat version (RHEL/CentOS/Fedora). Add the following lines to the bottom of /etc/postfix/main.cf smtpd_use_tls = yes smtpd_tls_cert_file = /etc/pki/tls/certs/server.crt smtpd_tls_key_file = /etc/pki/tls/private/server.key smtpd_tls_CAfile = /etc/pki/tls/certs/ca_bundle.crt smtpd_tls_loglevel = 3 smtpd_tls_received_header = yes smtpd_tls_session_cache_timeout = 3600s smtpd_tls_session_cache_database
