From: test@example.com
MIME-Version: 1.0
To: test@example.com
Subject: Test
Content-Type: multipart/mixed;
 boundary="------------040103020004000509010404"

This is a multi-part message in MIME format.
--------------040103020004000509010404
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: quoted-printable

This is a test.
--------------040103020004000509010404
Content-Type: text/plain;
 name="test.txt"
Content-Transfer-Encoding: base64
Content-Disposition: inline;
 filename="test.txt"

MTIzCg==
--------------040103020004000509010404--