diff -urN mutt-1.5.23.orig/send.c mutt-1.5.23/send.c
--- mutt-1.5.23.orig/send.c 2014-10-12 16:55:39.680846728 +0200
+++ mutt-1.5.23/send.c 2014-10-12 16:55:52.104179682 +0200
-@@ -557,7 +557,11 @@
- if ((flags & SENDGROUPREPLY) && (!in->mail_followup_to || hmfupto != M_YES))
+@@ -672,7 +672,7 @@
+ (!in->mail_followup_to || hmfupto != MUTT_YES))
{
- /* if(!mutt_addr_is_user(in->to)) */
-- rfc822_append (&out->cc, in->to, 1);
-+ if (option (OPTKEEPTO)) {
-+ rfc822_append (&out->to, in->to, 1);
-+ } else {
-+ rfc822_append (&out->cc, in->to, 1);
-+ }
- rfc822_append (&out->cc, in->cc, 1);
- }
- }
+ /* if (!mutt_addr_is_user(in->to)) */
+- if (flags & SENDGROUPREPLY)
++ if ( (flags & SENDGROUPREPLY) || ! option(OPTKEEPTO) )
+ rfc822_append (&out->cc, in->to, 1);
+ else
+ rfc822_append (&out->to, in->to, 1);
diff -ur mutt-1.5.23.orig/init.h mutt-1.5.23/init.h
--- mutt-1.5.23.orig/init.h 2014-10-12 17:17:05.716118306 +0200
+++ mutt-1.5.23/init.h 2014-10-12 17:24:08.119438749 +0200