<message>
<header>
<field>
MIME-Version: 1.0</field>
<field>
Content-Type: message/rfc822</field>
<field>
Subject: the body is a base64 encode rfc822 message including another base64 encoded rfc822 message</field>
<field>
Content-Transfer-Encoding: base64</field>
</header>
<message>
<header>
<field>
MIME-Version: 1.0</field>
<field>
Subject: a simple rfc822 message encoded in a base64 body.</field>
<field>
Content-Type: message/rfc822</field>
<field>
Content-Transfer-Encoding: base64</field>
</header>
<message>
<header>
<field>
Content-Type: text/plain; charset=us-ascii</field>
<field>
Content-Transfer-Encoding: 7bit</field>
</header>
<body>
Text body

</body>
</message>
</message>
</message>