Subject: Sample mail
From: John Doe <jdoe@machine.example>
To: Mary Smith <mary@example.net>
Date: Fri, 21 Nov 1997 09:55:06 -0600
Content-Type: multipart/mixed; boundary="0000MAIN"

main summary

--0000MAIN
Content-Type: text/plain

1. main message

--0000MAIN
Content-Type: application/octet-stream
Content-Disposition: inline; filename="main_signature.sig"
Content-Transfer-Encoding: base64

aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==

--0000MAIN
Subject: Inside mail 3
From: Mary Smith <mary@example.net>
To: John Doe <jdoe@machine.example>
Date: Fri, 20 Nov 1997 09:55:06 -0600
Content-Type: multipart/mixed; boundary="0003MSG"

3. message summary

--0003MSG
Content-Type: text/plain

3.1 message text

--0003MSG
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="msg_3_signature.sig"
Content-Transfer-Encoding: base64

aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==

--0003MSG--

--0000MAIN
Content-Type: multipart/mixed; boundary="0004ATTACH"

4 attach summary

--0004ATTACH
Content-Type: image/gif
Content-Disposition: attachment; filename="att4.1_gif.sig"
Content-Transfer-Encoding: base64

aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==

--0004ATTACH
Subject: Inside mail 4.2
From: Mary Smith <mary@example.net>
To: John Doe <jdoe@machine.example>
Date: Fri, 10 Nov 1997 09:55:06 -0600
Content-Type: multipart/mixed; boundary="0042MSG"

4.2 message summary

--0042MSG
Content-Type: text/plain

4.2.1 message text

--0042MSG
Content-Type: multipart/alternative; boundary="0422ALTER"

4.2.2 alternative summary

--0422ALTER
Content-Type: text/plain

4.2.2.1 plain text

--0422ALTER
Content-Type: text/html

<h1>4.2.2.2 html text</h1>

--0422ALTER--

--0042MSG--

--0004ATTACH--

--0000MAIN--