To: foo@example.com
Subject: multipart
Date: Sun, 01 Jan 2000 01:00:00 +0000
From: normal@example.com
Content-type: multipart/alternative; boundary="normal-multipart"
MIME-version: 1.0

multipart message
--normal-multipart
Content-type: text/html

<html>
<head><style>
body{background:#008;color:white}
em{color:#f88}
</style></head>
<body>Again a <em>simple</em> message</body>
</html>
--normal-multipart
Content-type: text/plain

Again a simple message
--normal-multipart--