--- ./Handlers/CookHeaders.py	2007-02-28 22:35:58.000000000 +0100
+++ /tmp/CookHeaders.py	2007-04-25 23:31:41.000000000 +0200
@@ -115,7 +115,7 @@
     # augment it.  RFC 2822 allows max one Reply-To: header so collapse them
     # if we're adding a value, otherwise don't touch it.  (Should we collapse
     # in all cases?)
-    if not fasttrack:
+    if not fasttrack and not (mlist.leave_existing_reply_to_alone and msg.has_key('reply-to')):
         # A convenience function, requires nested scopes.  pair is (name, addr)
         new = []
         d = {}