Can't find what you need? Try....Google
Page 1 Exchange of email using TCP/IP

This Page Basically, email consist of:
1.The envelope 2.Headers 3.Message body


1.The Envelope

rfc 821 specifies the contents and interpretation of the envelope--used by the MTA's for delivery specified by these two SMTP commands:
MAIL From: and RCPT To:

MAIL From:<>
RCPT To:<>

2. Headers


Headers are used by the User Agent and each header field contains a name, followed by a colon, followed by the field value.
Received: by (4.1/SMI-4.1)
id AA01301; Tue, 21 May 98 11:37:22 MST

Message-Id: <>
From: (Mable Merliney)
X-Phone: +0 202 671 2761
X-Mailer: Mail Userís Shell (9.1.0 12/02/98)
Subject: testing

eMail CRM Freeware I recommend it. It maximize the life-time value of my customers--Quick Tour
emails Art of eMail CRM How to apply minimum efforts for maximum result
at the shortest time?
eMail Bolts & Nuts Interesting emails stuff that you should  know eMail Broadcasting
eMail Marketing Tips Great email marketing strategies and ideas to help you increase sales
Sun Tzu Free eBook Sun Tzu Art of War Leaders without thoughtful strategy invite defeat.
Useful Web Sites
Freeware, shareware tools to help you speed-up your Internet connection
Guest Book  |  Minute Wisdom
Filled with stolen moments, lost dreams, and too many 'if only'
User Agent - Any program like: Eudora, MS Outlook, Gmail, Yahoo-mail or editor that let users create, edit, compose, store, send mails to a mail server , polls a mail server for mails, download and display mails and use POP3 to talk to Mail server.
Headers beginning with an X- are user-defined fields. RFC 822 specifies the format and interpretation of the header fields.

3. Message body - It is the content of the message from the sender to the recipient and transferred using the DATA command--the Headers are sent first, followed by a blank line, followed by the body. Each line transferred using the DATA command must be less than 1000 bytes.

Notes: Command is a request for mail service action sent by the sender SMTP to the receiver SMTP.

The User Agent takes what the sender specify as a body, adds some headers and passes the result to the MTA

The MTA adds a few headers, adds the envelope and sends the result to another MTA.

Notes: The term "content" used, normally means the combination of headers and the body--which is sent by the client with the DATA command.

SMTP have a few more commands: SEND command   SOML command   SAML command begins a mail transaction, once started, a


Mike Enlow
Online Stealth
Marketing eBook


100% effective.
I recommend it.

  An easy way
stop spam getting
into your PC

mail transaction which consists of HELO, MAIL FROM and one or more RCPT command, follows by the DATA command.

SEND SOML SAML replaces the MAIL command and allow mails to be delivered directly to the recipient mailbox or user terminal.

Help command ask the receiver machine to send help information to the sender HELP request command.

RSET command that aborts current mail transaction and causes both ends to reset and any stored information about sender, recipients or mail data is discarded.

VRFY command lets the client ask the sender to verify a recipient address, identifies a user, name, specified mailbox and returned a reply, without sending mail to the recipient.

NOOP command force the server to respond with an OK reply code 200 - NOOP command does nothing else.

EXPN expands a mailing list, asks the receiver to confirm that the argument identifies a mailing list, and if yes, return the membership of that list with full name of the users and specified mailboxes.

TURN command lets the client and server switch roles, to send mail in the reverse direction without having to create a new one TCP connection. The receiver must send an OK reply and then take on the role of the sender-SMTP or send a refusal 502 reply and retain the role of the receiver-SMTP.

HELP  NOOP   EXPN  and VRFY command
can be used at any time during a session between SMTP mail machine.

See Basic email delivery or How Email Works?

This Page 2
Basically, email consist of:
1.The envelope 2.Headers 3.Message body

See Page 1 Exchange of email using TCP/IP




valued contribution
that I and the rest of my team sincerely appreciate it. We have checked your software twice and it is good." Alex










Free Secrets of International Trade
Every thing you wanted to know about International import export
Free 2Try e-Book "I am a Japanese international business consultant. I find your International Export Import Guide Manual fantastic and splendid." Tominaga Shintaro, Global Business Management Consultant