diff -rupN mailman-2.1.18-1/Mailman/Handlers/CleanseDKIM.py mailman-2.1.18-1.orig/Mailman/Handlers/CleanseDKIM.py
--- mailman-2.1.18-1/Mailman/Handlers/CleanseDKIM.py	2014-08-30 00:05:29.756265182 +0200
+++ mailman-2.1.18-1.orig/Mailman/Handlers/CleanseDKIM.py	2014-05-06 18:43:56.000000000 +0200
@@ -31,10 +31,10 @@ from Mailman import mm_cfg
 def process(mlist, msg, msgdata):
     if not mm_cfg.REMOVE_DKIM_HEADERS:
         return
-    if ( ( mm_cfg.REMOVE_DKIM_HEADERS == 1 and
+    if (mm_cfg.REMOVE_DKIM_HEADERS == 1 and
            (msgdata.get('from_is_list') == 1 or
             (mlist.from_is_list == 1 and msgdata.get('from_is_list') != 2)
-           ) ) or ( mm_cfg.mm_cfg.REMOVE_DKIM_HEADERS == 2 )
+           )
        ):
         del msg['domainkey-signature']
         del msg['dkim-signature']