+.ifdef USE_TLS
+tls_certificate = /etc/exim4/ssl/thishost.crt
+tls_privatekey = /etc/exim4/ssl/thishost.key
+.ifdef RELAY_HOST
+tls_try_verify_hosts = *
+tls_verify_certificates = /etc/exim4/ssl/ca.crt
+tls_crl = /etc/exim4/ssl/ca.crl
+.endif
+.endif
+