Sams Teach Yourself TCP/IP in 24 Hours, Fourth Edition

Email Format

Your email reader application assembles a message into the format necessary for Internet transmission. An email message sent over the Internet consists of two parts: the header and the body.

Like the body of the message, the header is transmitted as ASCII-based text. The header consists of a series of keyword field names followed by one or more commaseparated values. Most of the mail header fields are familiar to anyone who has worked with email. Some of the important header fields are given in Table 18.1.

Table 18.1. Some Important Mail Header Fields

Header Field	Description
To:	Email address(es) of mail recipient(s).
From:	Email address of sender.
Date:	Date and time the message was sent.
Subject:	A brief description of the message subject. ...