diff --git a/tmail/Dockerfile b/tmail/Dockerfile
index d95caaa..219d564 100644
--- a/tmail/Dockerfile
+++ b/tmail/Dockerfile
@@ -24,7 +24,8 @@ ENV MAIL_PASS admin
 VOLUME /var/mail
 EXPOSE 25 110
 
-CMD twistd -n mail --smtp=tcp:25 \
+CMD twistd -n mail --esmtp \
+                   --smtp=tcp:25 \
                    --pop3=tcp:110 \
                    --maildirdbmdomain=$MAIL_NAME=$MAIL_PATH \
                    --user=$MAIL_USER=$MAIL_PASS \