Index: Decorate.py
===================================================================
--- Decorate.py	(revision 8147)
+++ Decorate.py	(working copy)
@@ -1,4 +1,4 @@
-# Copyright (C) 1998-2006 by the Free Software Foundation, Inc.
+# Copyright (C) 1998-2007 by the Free Software Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
@@ -115,9 +115,15 @@
                     payload = payload.encode(mcset)
                     newcset = mcset
                     # if this fails, fallback to outer try and wrap=true
+            format = msg.get_param('format')
+            delsp = msg.get_param('delsp')
             del msg['content-transfer-encoding']
             del msg['content-type']
             msg.set_payload(payload, newcset)
+            if format:
+                msg.set_param('Format', format)
+            if delsp:
+                msg.set_param('DelSp', delsp)
             wrap = False
         except (LookupError, UnicodeError):
             pass
Index: Scrubber.py
===================================================================
--- Scrubber.py	(revision 8147)
+++ Scrubber.py	(working copy)
@@ -1,4 +1,4 @@
-# Copyright (C) 2001-2006 by the Free Software Foundation, Inc.
+# Copyright (C) 2001-2007 by the Free Software Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
@@ -380,7 +380,13 @@
                 text.append(t)
         # Now join the text and set the payload
         sep = _('-------------- next part --------------\n')
+        format = msg.get_param('format')
+        delsp = msg.get_param('delsp')
         replace_payload_by_text(msg, sep.join(text), charset)
+        if format:
+            msg.set_param('Format', format)
+        if delsp:
+            msg.set_param('DelSp', delsp)
     return msg