Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

The whole site in one document for easy reference!
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP Electronic Mail System: Concepts and Protocols (RFC 822, MIME, SMTP, POP3, IMAP)
                     9  TCP/IP Electronic Mail Message Formats and Message Processing: RFC 822 and MIME
                          9  TCP/IP Enhanced Electronic Mail Message Format: Multipurpose Internet Mail Extensions (MIME)

Previous Topic/Section
MIME Content-Type Header and Discrete Media: Types, Subtypes and Parameters
Previous Page
Pages in Current Topic/Section
1234
5
6
Next Page
MIME Content-Transfer-Encoding Header and Encoding Methods
Next Topic/Section

MIME Composite Media Types: Multipart and Encapsulated Message Structures
(Page 5 of 6)

Example Multipart Message

Table 248 contains a specific example of a multipart message (with portions abbreviated to keep length down), so you can see what one looks like in text form. (If you want to see more, you probably have several in your own e-mail inbox right now!)


Table 248: Example MIME Multipart Message

From: Joe Sender <joe@someplace.org>
To: Jane Receiver <jane@somewhereelse.com>
Date: Sun, 1 Jun 2003 13:28:19 —0800
Subject: Photo and discussion
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="exampledelimtext123"

This is a multipart message in MIME format

—exampledelimtext123
Content-Type: text/plain

Jane, here is the photo you wanted me for the new client.
Here are some notes on how it was processed.
(Blah blah blah…)
Talk to you soon,
Joe.

—exampledelimtext123

Content-Type: image/jpeg; name="clientphoto.jpg"
Content-Transfer-Encoding: base64

SDc9Pjv/2wBDAQoLCw4NDhwQEBw7KCIoOzs7Ozs7Ozs

zv/wAARCADIARoDASIAAhEBAxEB/8QAHAAAAQUBA

—exampledelimtext123

(Epilogue)


In this example, Joe is sending Jane a multipart message containing a JPEG photograph and some explanatory text. The main header of the message specifies the multipart/mixed type and a boundary string of “exampledelimtext123”. The message begins with the preamble, which is ignored by the recipient e-mail client but can be seen by the human reader. It is common to put a string here such as the one given in this example. That way, if a person using a client that does not support MIME receives the message, the recipient will know what it is.

The first delimiter string is then placed in the message, followed by the first body part, the text Joe is sending Jane. This is preceded by whatever headers are needed by the body part, in this case Content-Type: text/plain. (Note, however, that this is the default in MIME, so it could be omitted here.) After the text message is another delimiter and then the encoded JPEG photo in the second body part, with its own headers. Finally, one more delimiter and then a space for the epilogue. This is ignored if present, and is often not used at all.

It is possible to send a “multipart” message that has only a single body part. This is sometimes done to take advantage of the preamble area to provide information about how to decode a non-text media type. Of course, this can also be done by including such text decoding instructions as a body part.


Previous Topic/Section
MIME Content-Type Header and Discrete Media: Types, Subtypes and Parameters
Previous Page
Pages in Current Topic/Section
1234
5
6
Next Page
MIME Content-Transfer-Encoding Header and Encoding Methods
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.