erp5_interface_post: update InternetMessagePost_ingest

bt5/erp5_interface_post/SkinTemplateItem/portal_skins/erp5_interface_post/InternetMessagePost_ingest.py

@@ -30,3 +30,7 @@ if strict_causality_reference != None:
     # If causality has a follow up (ie: on a Support Request), then they most
     # likely share the same follow up
     mail_message.setDefaultFollowUp(causality_event.getDefaultFollowUp())
+
+mail_message.stop()
+
+return [mail_message,]