发送到我们公司服务器的任何邮件的“来自”域的邮件标题将被服务器的域名替换。
例如：
example@gmail.com发送电子邮件到我们的服务器（company.com）。我们看到此电子邮件的发件人是example@company.com。
我不知道原因。请帮我。谢谢！
两个例子：
163：
From example@company.com Wed Dec 21 21:47:26 2016
Return-Path: <example@company.com>
Received: from m13-141.163.com (m13-141.163.com [220.181.13.141])
by company.com (8.14.3/8.14.3/Debian-9.1ubuntu1) with ESMTP id uBLDlPiQ013409
for <xxx@company.com>; Wed, 21 Dec 2016 21:47:26 +0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com;
s=s110527; h=Date:From:Subject:MIME-Version:Message-ID; bh=hpaD0
qA4I59smafOVhBxwFe3a15FCNfA2uxigC6sgOY=; b=JdNTQe6QHM1TCcgvPCHtw
0Lkr1iMuJpydrsSpywGH8QnwV0hMucgh0IO+jg4THKW+2hr/IaVbQJoJabx2W/Mr
nQ2YWwc7ECDVaFqU9HJJygtqcrP3d2cp3qBbGlq/YVUUkXidTeX52kQStnULVBzk
FEJFuAYeRA/4XZyeo5LxNM=
Received: from example$163.com ( [192.198.95.71, 54.215.2.217, 10.144.1.72] )
by ajax-webmail-wmsvr141 (Coremail) ; Wed, 21 Dec 2016 21:46:07 +0800 (CST)
X-Originating-IP: [192.198.95.71, 54.215.2.217, 10.144.1.72]
Date: Wed, 21 Dec 2016 21:46:07 +0800 (CST)
From: "example" <example@company.com>
To: "xxx@company.com" <xxx@company.com>
Subject: aaaaa
X-Priority: 3
X-Mailer: Coremail Webmail Server Version SP_ntes V3.5 build
20160729(86883.8884) Copyright (c) 2002-2016 www.mailtech.cn 163com
X-CM-CTRLDATA: RB7qyGZvb3Rlcl9odG09MjcyNTo1Ng==
Content-Type: multipart/alternative;
boundary="----=_Part_12111914_355555859.1482327967157"
MIME-Version: 1.0
Message-ID: <7e744d1.2de269.15921a1c5b6.Coremail.xysmlx@163.com>
X-Coremail-Locale: zh_CN
X-CM-TRANSID:jcGowACXpqKfh1pYSOaiAA--.29831W
X-CM-SenderInfo: p01vzzr06rljoofrz/1tbiNQ1HvlSIRLiDogABsB
X-Coremail-Antispam: 1U5529EdanIXcx71UUUUU7vcSsGvfC2KfnxnUU==
Status: RO
X-UID: 336
Content-Length: 4432
的Gmail：
From example@company.com Wed Dec 21 22:52:39 2016
Return-Path: <example@company.com>
Received: from mail-ua0-f178.google.com (mail-ua0-f178.google.com [209.85.217.178])
by company.com (8.14.3/8.14.3/Debian-9.1ubuntu1) with ESMTP id uBLEqbPm019461
for <xxx@company.com>; Wed, 21 Dec 2016 22:52:38 +0800
Received: by mail-ua0-f178.google.com with SMTP id 2so79983525uax.2
for <xxx@company.com>; Wed, 21 Dec 2016 06:52:00 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20161025;
h=mime-version:from:date:message-id:subject:to;
bh=+fBXgxbVSyjlxMpSNMOsZLbhE2bqAQI97mJviWO7ebE=;
b=l1SM9poejQhkOB7y725tK1K8oCsbxSENpl+po0nU+AHzyNE0BguFHgLLrFMj7vnuPG
ARR0mhWhVow3Pikzeq+IrymrsbnEqyOwgehR/ztTYDY8TPfpghK3O7eRPr9XVhC8oFs+
Il9rCu324IljhOstd/5cWhGkwhA/m2F1bLUoxYw0O18GLVE85uQnH7PZe04W21vPLDVq
fuJlrbNFSo4Fxbe626IaS/1CVIUrs5Wkz1YExfa7pADbiqc3RNrEErBrk4FfWRPdHN/y
7z7PxqpHvBs+SG2IMx5eCRA5zdsczQvNXHIy3yIHvwkeydYi77PPzR8qUZ2pSfomzmKu
LKCg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:from:date:message-id:subject:to;
bh=+fBXgxbVSyjlxMpSNMOsZLbhE2bqAQI97mJviWO7ebE=;
b=CzacaxE4CvL4uxlG4qUkbEm+vAiix3+UR+I7D0xechpMyOGoGrjE/rVfOXl/Zk+8Rr
+F4xjJ+kTd7jv1C5d1NGk7CtjMl8mZpUk2bE7WesYV8PryUbY7b6mHpB7XjL3J3AD90o
UVPpyX9vjeVJ89E03a1rg05yILGEHWh/E3+bByw68HPxdyCss2I0Tri98030QBWRHasj
7BX6qswHzpo2+87yvRpcsBqoSoKgz4L7ydPMt+zXCmxN2VCqw5MX6vLyzuaOIyWR6RFd
Uda7z9lqKw8bOo1ntxaMSTwiHmRWZyWtarvB/1MxPRySsJDIc+4tw1YLbfBNNYiWf3C8
/SMQ==
X-Gm-Message-State: AIkVDXKc6Fge9ySWKwRQDYsVUzsuNqgZ9VBci7aM/TEGB915XFQonbYpgBCqBzht712z1QTbDXlrek9X6dKWfA==
X-Received: by 10.176.85.139 with SMTP id v11mr632414uaa.7.1482331912496; Wed,
21 Dec 2016 06:51:52 -0800 (PST)
MIME-Version: 1.0
Received: by 10.176.16.145 with HTTP; Wed, 21 Dec 2016 06:51:12 -0800 (PST)
From: example <example@company.com>
Date: Wed, 21 Dec 2016 22:51:12 +0800
Message-ID: <CAO+bwXcoowGtdtZBsQB44K27gUtCJEbpuRKpPj=w66YDQE828g@mail.gmail.com>
Subject: fdasfdasfdasdasffdas
To: xxx@company.com
Content-Type: multipart/alternative; boundary=f403045e286e156bca05442c4b0d
X-UID: 340
Status: RO
Content-Length: 2500