MIME - Multipurpose Internet Mail Extensions

From: Someone 
To: nobody@nrao.edu
Subject: A sample MIME message
Date: Fri, 12 Sep 1998 12:20:52 -0400 (EDT)
Mime-Version: 1.0
Content-Type: MULTIPART/MIXED; BOUNDARY="0-1836658841-826127272=:25689"
Content-Length: 5068

  This message is in MIME format.  Many mailers put a little blurb in
  here that describes how to read it; some just leave it blank or say 
  that it's in MIME.

--0-1836658841-826127272=:25689
Content-Type: TEXT/PLAIN; charset=US-ASCII


This is a simple piece of text; it can obviously be read without 
resorting to a MIME-capable mail reader, though the extra mime "armor"
looks weird.

--0-1836658841-826127272=:25689
Content-Type: TEXT/PLAIN; charset=US-ASCII; name="foobar.txt"
Content-Transfer-Encoding: BASE64
Content-ID: <Pine.OSF.3.91.960306104752.25689B@rgalp0>
Content-Description: an encoded file

DQpGSVRMRCBib21iZWQgaW4gVFNUKDE1SkFOOTYpIG9uIGFscDQsIHdpdGgg
YW4gZXJyb3IgdGhhdCBJDQpoYXZlIG5ldmVyIGJlZm9yZSBzZWVuLiBUaGUg
ZHVtcCBvZiB0aGUgYWJvcnRlZCBydW4gZm9sbG93cy4NCkFmdGVyIHRoZSBl
...

(rest of encoded file omitted)