如何分析出pop3邮件里发送者的公网IP?

[iocpserver1]

如何分析出pop3邮件里发送者的公网IP?
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+OK 2346 octets
Received: from mail-iw0-f169.google.com (unknown [209.85.214.169])
by mx39 (Coremail) with SMTP id 3tGowKDL3G7P5sRMQVEyAA--.38S2;
Mon, 25 Oct 2010 10:09:21 +0800 (CST)
Received: by iwn42 with SMTP id 42so46342iwn.14
for <[e-mail]>; Sun, 24 Oct 2010 19:09:25 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.231.169.203 with SMTP id a11mr5146101ibz.99.1287972564838;
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Received: by 10.231.30.72 with HTTP; Sun, 24 Oct 2010 19:09:24 -0700 (PDT)
Date: Mon, 25 Oct 2010 10:09:24 +0800
Message-ID: <[e-mail]>
Subject: =?GB2312?B?1f3Kvb+otcRmaWxlNc7EvP4=?=
From: =?GB2312?B?0OzB6NTG?= <[e-mail]>
To: [e-mail]
Content-Type: multipart/mixed; boundary=0016e68dec3b352c800493677b44
X-Coremail-Antispam: 1Uf129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73
VFW2AGmfu7bjvjm3AaLaJ3UbIYCTnIWIevJa73UjIFyTuYvjxU0xR6DUUUU

--0016e68dec3b352c800493677b44
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+OK 155878 octets
Received: from m15-95.126.com (unknown [220.181.15.95])
by mx28 (Coremail) with SMTP id TsCowLD7v7GgtD1MpwxbAA--.1749S2;
Wed, 14 Jul 2010 20:59:12 +0800 (CST)
Received: from wy60650507 ( [222.183.84.41] ) by ajax-webmail-wmsvr95
(Coremail) ; Wed, 14 Jul 2010 20:59:09 +0800 (CST)
Date: Wed, 14 Jul 2010 20:59:09 +0800 (CST)
From: =?gbk?B?zfXT7g==?= <[e-mail]>
To: =?gbk?B?1Kq80Q==?= <[e-mail]>, =?gbk?B?1tzRp7fn?= <[e-mail]>
Message-ID: <[e-mail]>
Subject: =?gbk?B?tefX07Hqx6kytM63otDQt72wuA==?=
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_Part_216521_24385670.1279112349368"
X-Originating-IP: [222.183.84.41]
X-Priority: 3
X-Mailer: Coremail Webmail Server Version SP_ntes V3.5 build
100525(10833.3107.3105) Copyright (c) 2002-2010 www.mailtech.cn 126com
X-CM-CTRLDATA: 2uG5dGZvb3Rlcl9odG09NDo0NA==
X-CM-TRANSID:X8qowLArnQOdtD1MgUAEAA--.11292W
X-CM-SenderInfo: dz1wilqvqvila6rslhhfrp/1tbivAoNyUgYuHO1YgABs-
X-Coremail-Antispam: 1Uf129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73
VFW2AGmfu7bjvjm3AaLaJ3UbIYCTnIWIevJa73UjIFyTuYvjxU44EEUUUUU

------=_Part_216521_24385670.1279112349368
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以上是两封邮件的pop3 Header，格式不一致，究竟哪个标志表示pop3邮件发送者的公网IP?

[grf9527]

Received: from mail-iw0-f169.google.com (unknown [209.85.214.169])

我记忆中是这个，不过不是很确定了，你查一下标准吧。

[iocpserver1]

有的邮件根本没Received: from mail-iw0-f169.google.com (unknown [209.85.214.169])