localhost and 127.0.0.1 in headers

[klowet]

Hi

When I sent emails through PMG, I see 'localhost' and '127.0.0.1' in the headers. Any idea where they come from?

ARC-Authentication-Results: i=1; mx.google.com;
       spf=pass (google.com: domain of dashboard@mydomain.com designates 154.42.x.x as permitted sender) smtp.mailfrom=dashboard@mydomain.com
Return-Path: <dashboard@mydomain.com>
Received: from pmg01.mydomain.com (pmg01.mydomain.com. [154.42.x.x])
        by mx.google.com with ESMTPS id r6si759480eda.197.2019.07.09.22.33.46
        for <xx@xx.com
        (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256);
        Tue, 09 Jul 2019 22:33:47 -0700 (PDT)
Received-SPF: pass (google.com: domain of dashboard@mydomain.com designates 154.42.x.x as permitted sender) client-ip=154.42.x.x;
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of dashboard@mydomain.com designates 154.42.x.x as permitted sender) smtp.mailfrom=dashboard@mydomain.com
Received: from pmg01.mydomain.com (pmg01.mydomain.com [127.0.0.1]) by pmg01.mydomain.com (Proxmox) with ESMTP id A7BC860FDE for <xx@xx.com; Wed, 10 Jul 2019 07:33:46 +0200 (CEST)
Date: Wed, 10 Jul 2019 07:33:46 +0200
To: Test User1 <xx@xx.xx>
From: Sender <noc@mydomain.com>
Reply-To: Sender <noc@mydomain.com>
Subject: Client:Welcome to Portal
Message-ID: <25da6ed9b6293552e5742f6b585275db@localhost.localdomain>

Thanks

 

[heutger]

maybe because PMG is running the pmg-smtp-filter post queue, so all mails are directed through this filter by PMG. In other words, mail go this way: outside - PMG than PMG 127.0.0.1 loop for content scan than PMG to destination host