- /* When we have detected Reply-To munging, we ignore the Reply-To
- * field (because it appears in the To or Cc headers) and use the
- * From header so that person will get pinged and will actually
- * receive the response if not subscribed to the list. Note that
- * under no circumstances does this fail to reply to the address in
- * the Reply-To header.
+ /* Some mailing lists munge the Reply-To header despite it being A Bad
+ * Thing, see http://www.unicom.com/pw/reply-to-harmful.html
+ *
+ * The munging is easy to detect, because it results in a
+ * redundant reply-to header, (with an address that already exists
+ * in either To or Cc). So in this case, we ignore the Reply-To
+ * field and use the From header. Thie ensures the original sender
+ * will get the reply even if not subscribed to the list. Note
+ * that the address in the Reply-To header will always appear in
+ * the reply.