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!

Searchable, convenient, complete TCP/IP information.
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)

Previous Topic/Section
TFTP Message Formats
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP/IP Electronic Mail System Overview and Concepts
Next Topic/Section

TCP/IP Electronic Mail System: Concepts and Protocols (RFC 822, MIME, SMTP, POP3, IMAP)

It is common for human beings to create systems that are reminiscent of ones to which they are already accustomed. We are all accustomed to using the regular mail system to send letters and other documents from our location to recipients anywhere that the postal system serves. Naturally, one of the first applications of internetworks was to create an electronic version of this conventional mail system that would allow messages to be sent in a similar manner, but more quickly and easily. Over the course of many years, an electronic mail system for TCP/IP was created and refined. It is now the most widely used means of electronic messaging in the world.

In this section I describe TCP/IP electronic mail in detail, in five sections that discuss electronic mail concepts and the various components and protocols that comprise the overall TCP/IP e-mail system. The first subsection provides an overview of TCP/IP electronic mail and discusses the way that it is used and the different protocols and methods that comprise the system. The second discusses how e-mail messages are addressed, and the third covers standard and special formats for e-mail messages. The fourth and fifth subsections describe the TCP/IP protocols that implement electronic mail functionality. This includes an examination of the Simple Mail Transfer Protocol (SMTP), which is responsible for the delivery of e-mail, and several protocols and methods used for mailbox access and mail retrieval, including POP3 and IMAP.

Note: This discussion focuses primarily on the mechanisms used for electronic mail composition, delivery and access in modern internetworks. In the e-mail overview topic I make mention of some techniques used in the past for TCP/IP electronic mail, but only briefly for historical completeness, and to contrast these methods to the ones presently used.


Quick navigation to subsections and regular topics in this section



Previous Topic/Section
TFTP Message Formats
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP/IP Electronic Mail System Overview and Concepts
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.