diff --git a/product/ERP5/Tool/NotificationTool.py b/product/ERP5/Tool/NotificationTool.py
index 92fe8931930eb371ced03d9afc2e71f81bd6cdd3..2f7c6012eb50c8c929f587779aad70e76a492cf7 100644
--- a/product/ERP5/Tool/NotificationTool.py
+++ b/product/ERP5/Tool/NotificationTool.py
@@ -166,8 +166,8 @@ def buildEmailMessage(from_url, to_url, msg=None,
 
     part.add_header('Content-Disposition',
                     'attachment; filename=%s' % attachment_name)
-    part.add_header('Content-ID',
-                    '%s' % attachment_name)
+    part.add_header('Content-ID', '<%s>' % \
+                    ''.join(['%s' % ord(i) for i in attachment_name]))
     message.attach(part)
 
   return message