Not sure if this was intentional or not, but here is a patch to remove a
"damned if you do, damned if you don't" situation.
Thanks,
Edgar
Index: mail.file.c
===================================================================
RCS file: /cvs/src/usr.sbin/smtpd/mail.file.c,v
retrieving revision 1.1
diff -u -p -u -r1.1 mail.file.c
--- mail.file.c 14 Feb 2017 16:43:28 -0000 1.1
+++ mail.file.c 25 Apr 2017 02:52:01 -0000
@@ -47,7 +47,7 @@ main(int argc, char *argv[])
if (argc == 0)
errx(1, "mail.file: filename required");
- if (argc != 0)
+ if (argc > 1)
errx(1, "mail.file: only one filename is supported");
file_engine(argv[0]);
