--- /sys/src/cmd/upas/send/filter.c	Sat Oct  5 02:35:28 2019
+++ filter.c	Sat Feb 20 23:33:14 2021
@@ -26,7 +26,7 @@
 int
 refuse(dest*, message *, char *cp, int, int)
 {
-	fprint(2, "%s", cp);
+	fprint(2, "%s\n", cp);
 	exits("error");
 	return 0;
 }