Add program description comment at the top.

diff --git a/mdeliver.c b/mdeliver.c
index a91ca99..ba7ca05 100644 (file)
--- a/mdeliver.c
+++ b/mdeliver.c
@@ -3,6 +3,16 @@
  * $Id$
  *
  * This program is in the public domain.
+ *
+ * mdeliver is a simple, robust MDA.  It delivers a single message
+ * from stdin to the user's Maildir and executes (in the background) a
+ * single program with the message filename as the first argument.
+ * Additional arguments may be specified; see main() below for
+ * details.
+ *
+ * This program does not conform strictly to POSIX.  However, the two
+ * nonstandard interfaces it relies upon (<err.h> and <sysexits.h>)
+ * are widespread and easily enough replaced if necessary.
  */
 
 #include <sys/types.h>