This is the preamble area

MIME-Version: 1.0
From: Nathaniel Borenstein <nsb@bellcore.com>
Subject: A multipart example
Content-Type: multipart/mixed;
boundary=unique-boundary-1
This is the preamble area of a multipart message. Mail readers that understand multipart format should ignore this preamble.
If you are reading this text, you might want to consider changing to a mail reader that understands how to properly display multipart messages. . --unique-boundary-1
...Some text appears here...
[Note that the preceding blank line means
no header fields were .given and this is text,
with charset US ASCII. It could have been
done with explicit typing as in the next part.]
--unique-boundary-1
Content-type: text/plain; charset=US-ASCII
This could have been part of the previous part, but illustrates explicit versus implicit typing of body parts.
--unique-boundary-1
Content-Type: multipart/parallel;


boundary=unique-boundary-2
--unique-boundary-2 Content-Type: audio/basic Content-Transfer-Encoding: base64
... base64-encoded 8000 Hz single-channel u-law-format audio data goes here....
--unique-boundary-2
Content-Type: image/gif
Content-Transfer-Encoding: Base64
... base64-encoded image data goes here.... --unique-boundary-2--
--unique-boundary-1 Content-type: text/richtext
This is <boldxitalic>richtext.</italicx/bold> <nlxnl>Isn't it <biggerxbigger>cool?</biggerx/big-ger>
--unique-boundary-1 Content-Type: message/rfc822
From: (name in US-ASCII) Subject: (subject in US-ASCII) Content-Type: Text/plain; charset=ISO-8859-1. Content-Transfer-Encoding: Quoted-printable
... Additional text in ISO-8859-1 goes here ... --unique-boundary-1--
Подводя итоги, еще раз следует отметить, что стандарт MIME позволяет расширить область применения электронной почты, обеспечить доступ к другим информационным ресурсам сети в стандартных форматах.