Headers: System account impersonation with empty sender address

type.inbound
and sender.email.email == ""
and (
  strings.icontains(sender.display_name, "mailer-daemon")
  or strings.icontains(sender.display_name, "postmaster")
)
and not (
  (
    any(ml.nlu_classifier(body.current_thread.text).topics,
        .name == "Bounce Back and Delivery Failure Notifications"
        and .confidence == "high"
    )
    or regex.icontains(subject.subject, 'Undeliver(?:ed|able)')
    or regex.icontains(subject.subject, 'Mensagem não entregue') // portuguese bounce back variant 
    or regex.icontains(subject.subject, '系统退信') // chinese bounce back variant 
  )
)