DKIM 서명을 깨지 않고 수신된 이메일에 날짜를 추가하는 방법: 헤더

일부 서버는 날짜 헤더 없이 이메일을 보내는데 Thunderbird는 날짜를 인식하지 못합니다. 그래서 다음 설정을 사용하고 날짜 헤더를 추가하고 싶습니다.

local_header_rewrite_clients = permit_inet_interfaces, ermit_sasl_authenticated
always_add_missing_headers = yes

하지만postfix.org이로 인해 DKIM 서명이 깨질 수 있다고 합니다. DKIM 서명을 깨지 않고 날짜 헤더를 추가하는 방법이 있나요? (내 메일 서버는 DKIM을 사용합니다.)

날짜가 없는 헤더 이메일의 예:

Return-Path: <[email protected]>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on example.net
X-Spam-Level: ***
X-Spam-Status: No, score=3.7 required=8.0 tests=CONTENT_TYPE_PRESENT,
    FROM_MISSP_EH_MATCH,IP_LINK_PLUS,ISO2022JP_BODY,ISO2022JP_CHARSET,
        MISSING_DATE,MISSING_MID,NORMAL_HTTP_TO_IP,ONEGAI,QENCPTR1,RCVD_IN_DNSWL_NONE,
            RCVD_IN_MSPIKE_H2,RENRAKU,SPF_HELO_PASS,SPF_SOFTFAIL,TO_NO_BRKTS_FROM_MSSP
    autolearn=no autolearn_force=no version=3.4.0
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: from xxxxx.example.org (xxxxx.example.org [xxx.xxx.xxx.xxx])
    (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
    (No client certificate requested)
    by example.net (Postfix) with ESMTPS id D53991D45
    for <[email protected]>; Wed,  5 Sep 2018 20:44:48 +0900 (JST)
DKIM-Filter: OpenDKIM Filter v2.11.0 example.net D53991D45
Received: from xxxxx.example.org (xxxxx.example.org [xxx.xxx.xxx.xxx])
    by xxxxx.example.org (Postfix) with ESMTP id 77EFF8DC01
    for <[email protected]>; Wed,  5 Sep 2018 20:44:48 +0900 (JST)
Received: (qmail 23991 invoked by uid 101); 5 Sep 2018 20:44:43 +0900
Received: from unknown (HELO xxxxx.example.org) (xxx.xxx.xxx.xxx)
  by 0 with SMTP; 5 Sep 2018 20:44:43 +0900
Subject: ---email subject---
From: ---email subject---
To: ---email subject---
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-2022-JP
Content-Transfer-Encoding: 7bit
X-Mailer: Bap Version1
---email body---