diff --git a/docker/rootfs/start.sh b/docker/rootfs/start.sh
index 3f8d515..0792322 100644
--- a/docker/rootfs/start.sh
+++ b/docker/rootfs/start.sh
@@ -35,6 +35,8 @@ fi
 
 echo "[MAILSERVER]" >> /var/www/opentrashmail/config.ini
 echo "PORT=25" >> /var/www/opentrashmail/config.ini
+echo "MAILPORT=25" >> /var/www/opentrashmail/config.ini
+
 echo "[DATETIME]" >> /var/www/opentrashmail/config.ini
 echo "DATEFORMAT='D.M.YYYY HH:mm'" >> /var/www/opentrashmail/config.ini