diff --git a/rootfs/etc/confd/templates/main.cf.tmpl b/rootfs/etc/confd/templates/main.cf.tmpl
index 38324dd..6f54e6c 100644
--- a/rootfs/etc/confd/templates/main.cf.tmpl
+++ b/rootfs/etc/confd/templates/main.cf.tmpl
@@ -53,7 +53,7 @@ smtp_tls_session_cache_database = lmdb:${data_directory}/smtp_scache
 smtpd_sasl_type = dovecot
 smtpd_sasl_path = inet:{{getenv "DOVECOT_HOST"}}:{{getenv "DOVECOT_AUTH_PORT"}}
 smtpd_sasl_auth_enable = yes
-smtpd_sasl_security_options = noanonymous, noplaintext
+smtpd_tls_auth_only = yes
 smtpd_sasl_tls_security_options = noanonymous
 
 smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, defer_unauth_destination