寻找答案

这是用什么方法或者什么软件发送的邮件，很奇怪。
源信头如下:

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Wed, 14 May 2008 15:47:45 +0900 (JST)
From: =?GB2312?B?zsTX5sG8?= <zejouz@yellowweb.co.jp>
Subject: =?GB2312?B?cjM1N9HQt6LW0LjfsuO1xLnYvPy8qNCn1rix6jRJTlQ=?=
To: <!-- e --><a href="mailto:hrdl@neusoft.com">hrdl@neusoft.com</a><!-- e -->
Content-Type: multipart/mixed; charset="GB2312"; boundary="fxmKX57=_zhYbhCAldNvTwYOg1U6BSbUIa"
MIME-Version: 1.0
Date: Wed, 14 May 2008 14:47:52 +0800
Message-Id: <20080514064745.37C7B1220BF4@mail.yellowweb.co.jp>
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This is a multi-part message in MIME format

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