This material has been prepared to accompany the book "Searching and Researching on the Internet and the World Wide Web, Third Edition" (ISBN 1887902716) by Ernest Ackermann and Karen Hartman, and published by Franklin, Beedle and Associates, Incorporated, Wilsonville OR, ©2002. No part of this may be reproduced, stored in a retrieval system, or transcribed without permission of the publisher.

Email Basics

Electronic mail, or email, lets you communicate with other people on the Internet. Email is one of the basic Internet services, and by far the most popular. You can use it for any type of conversation; it's a way to keep in touch with friends, get information, start relationships, or express your opinion. Much of the time you'll be exchanging messages in plain text form (like the words on this page), but you can also exchange files in other formats such as spreadsheets, files for word processors, images, or programs. You can use email to join discussion groups and access other Internet services, but you can get to those other services using your Web browser as well. You can send messages to anyone with an Internet address, and likewise, you can receive email from anywhere on the Internet. With over 30 million people having some sort of connection to the Internet, you've got the opportunity to communicate with people nearby and around the world in a relatively quick and efficient manner.

You use a mail program on your computer to compose, send, and read email. Once you compose (write) a message, it's sent in electronic form, usually passing through several other sites on the Internet. Email is held at its destination until the person to whom it's addressed reads it, saves it in a file, or deletes it. The recipient does not have to be logged in or using a computer for the email to be delivered. When she does use her computer and checks for email, it will be delivered to her.

Email is a very convenient way to communicate with people; it's personal, and it seems everybody likes to get mail. Because email is used so often, it's worth spending some time to learn about how it works and its capabilities.

Here we focus on the basics of email. Some folks use Netscape Mail for email and some use other email programs, such as Microsoft Outlook Express, Eudora, cc:Mail, or Pine. Most email programs come with good online help.

Regardless of which you use, you'll have to understand many of the following topics:

How Email Works

Electronic mail lets you send and receive messages in electronic form. The person you communicate with could be any other user on the Internet, someone using the same computer system as you, or someone on a computer system thousands of miles away. The email is transmitted between computer systems, which exchange messages or pass them on to other sites according to certain Internet protocols or rules for exchanging email. You don't need to be concerned with many of the details; that's the computer's job. But you ought to know a little bit about the way email works.

Sending email is similar to sending something by a postal service. If you're sending a letter or a package to someone, you follow these steps:

  1. Write the letter or make up the package.
  2. Address it.
  3. Put on the proper postage or pay the charges to send it.
  4. Drop it off somewhere so it can be sent on its way and eventually delivered.
You don't care much about which methods are used to deliver it or what route it takes. You prepare what you want to send, address it, and hand it to the postal service or delivery company. You expect them to take care of the details of delivering the letter or package. With email you follow similar steps:
  1. Start an email program.
  2. Give the address of where to send the email.
  3. Compose a message using that email program.
  4. Give a command to send the message.
You've probably noticed that we've left out the part about adding postage and paying charges. Individual users don't pay a per message fee for email in many organizations-schools and companies-that have Internet access.

You use an email program to address, compose, and send the message. Email programs are called mail user agents because they act on the user's behalf. The user agent lets you prepare and send messages and also work with the mail you've received. The email program acts as a go-between with you and computer systems, and the computer systems handle the details of delivering and receiving mail. Once again, you don't have anything to do with how the mail is delivered.

Messages are sent from one site to another on the Internet in this way. When you compose your message, it's all in one piece, but when it's sent out to the Internet, it's divided into several pieces called packets. The number of packets depends on the size of the message. Each of the packets contains, among other things:

The packets are sent to the destination, passing through several Internet sites. Thousands of networks and millions of computers make up the Internet, and packets are passed from system to system. Each site accepts the packets addressed to it, but passes on the messages destined for another address. The packets can travel or arrive at their destination in any order, and they don't all have to take the same path. When you communicate with a remote site, you may think you have direct connection, but that's usually not the case. At the destination, the packets are collected and put in order, so the email appears to be in the same form it was sent. If there are errors in the packets or if some are lost, the destination sends a request back to the source asking for the message to be resent. All of this takes place according to SMTP, Simple Mail Transfer Protocol, the protocol the Internet uses to transport message between computer systems. SMTP uses TCP, Transmission Control Protocol, which provides a reliable means of communication.
To put it all in a nutshell: 
    A message sent by email is divided into packets, and the packets are sent (possibly by different paths and passing through different sites) to the destination, where they are reassembled into the original message
When you use Netscape on a personal computer that's using MS-Windows or if you're using a Macintosh, your computer isn't turned on all the time, so there has to be another computer system (one that's usually in fine running condition), called an email server, able to receive your mail at any time. In this case, that other system-perhaps the one at your Internet service provider or computer center-holds the email addressed to you until you start Netscape on your system and check to see if you've received any new email. Your computer sends email to the email server by SMTP, and the server system exchanges email with the rest of the Internet. When you check to see if there's any new email, another protocol, Post Office Protocol (POP), is used.

How Email is Exchanged between Computer Systems

Once a message is sent, it's put out on the Internet and usually delivered in a short time-minutes or seconds. But a few things could cause problems:

When you read your email, once again you use a program (a mail user agent) that helps you work with the messages you have waiting for you. On many systems you're told if you have email when you log in, you access the system you use to contact the Internet or start your system. The email messages can arrive at any time. They're added to a file, your mailbox or Inbox, which is part of a directory that holds all the email for the system. The packets making up an email message arrive at the email server, they're assembled, and then added to your mailbox. It holds all the messages on the server addressed to you, and only you can read your mail. If for some reason your mailbox gets scrambled, corrupted, or is changed so you can't read your mail, get in touch with the system administrator or call your Internet service provider. On many systems, all the users share the space allocated for the directory that holds email. Usually there's enough space to hold a lot of messages, but it's important that you delete old email messages and messages you've read so there is space to hold everybody's email.

Advantages and Limitations of Email


Email has a number of advantages over some other forms of communication. It's quick, convenient, and non intrusive.

Although there are some drawbacks to using email, it's still an effective and popular way to communicate.

Understanding Internet Email Addresses

An email address on the Internet usually has the form:


The local-address part is often the user's login name, the name you give to get in touch with your Internet server. That's followed by the character @, called the at sign. To its right is the domain name of the computer system that handles the email for the user. Sometimes the domain-name portion is the name of a specific computer such as It could be more general, such as, and in this case the systems at the site handle delivering mail to the appropriate computer. The portions or fields making up the domain name are separated by periods (the periods are called dots).

Here are two examples:

If you were going to tell someone the address, you would say ernie at oregano dot mwc dot edu. (Ernie and oregano are pronounced as a word, but mwc [em double-u see] and edu [e dee you] are pronounced as individual letters.)

When you know someone's email address, you have an idea of their login name and the name of the Internet site they use. You should be able to send email to postmaster at any Internet site. That's the address to use if you have questions about email to or from a specific host or site or general questions about a site. However, you may not get a quick response, since the person designated as postmaster usually has lots of other duties.

Dissecting Email-Headers, Message Body, Signature

One piece of email has three main parts:

  1. Headers
  2. Message body
  3. Signature
The headers are pieces of information that tell you and the email system several important things about a piece of email. Each header has a specific name and a specific purpose. You'll see some, but not necessarily all the headers each time you read a piece of email. They're all generated and put in the proper form by the email program you use, some with information from you, such as the address of the recipient, and some done automatically, such as the date.

When you read an email message, you're likely to see these headers. Here is a list of the most common headers.

The message body is the content of the email - what you send and what you receive. When you're sending email to a computer system where your message will be interpreted by a computer program, you'll be given instructions to use specific words or phrases in the message body. One time you might have to follow instructions like this when you subscribe to a discussion group. Here's an example:
TO SUBSCRIBE (UNSUBSCRIBE): Send email message to: 
The body of the message should read: Subscribe (unsubscribe) test-listproc your name 
The signature, which is optional, isn't a signed name but a sequence of lines, usually giving some information about the person who sent the email. It is made up of anything the user wants to include. Usually a signature has the full name of the sender and some information about how to contact the person by email, phone, or fax. Some signatures also contain a favorite quotation or some graphics created by typing characters from the keyboard. Make sure it's not too long. The longer it is, the more bytes or characters have to be sent, and so the more traffic to be carried on the Internet. It's fun to be creative and come up with a clever signature, but try to limit it to five lines.

Here's what I have in my signature file
Ernest Ackermann 
Department of Computer Science Mary Washington College 
Fredericksburg, VA 22401-5358 VOICE 540 - 654 - 1320  FAX   540 - 654 - 1068
You don't have to type in the signature each time. Email programs will automatically append the contents of a specified file to each outgoing message. The name of the file depends on the program you're using for email. Some common names are signature, sig, or signature.txt on computers that use Microsoft Windows as the operating system. On Unix systems the name SIG or .signature is often used. Most email programs allow you to specify what file to use as a signature, but you should check with a local expert about the precise name of the signature file. With Netscape, you set the name and location of the signature file by clicking on Edit in the menu bar, selecting Preferences, and then clicking on Mail & Groups, and then selecting Identity.

Finding Someone's Internet Email Address

Once you get the bug of communicating by email, you'll probably start to wonder about the email addresses of your friends, and there may be other times you'll want to know someone's email address. Some methods and services exist to help find email addresses, but none of them are guaranteed to produce satisfactory results every time.

The problem with finding someone's email address is that there is no central directory. If you were looking for someone's phone number, you'd either look in a phone book or call an information service. That approach usually works; everyone with a phone number usually receives a bill to pay for phone services, and even though there are lots of phone companies, each has up-to-date and readily available records. The situation on the Internet is much different. Many users don't pay any direct fees, and there isn't any central agency that registers each user. Users are added and deleted by individual Internet sites; the decisions are made locally. It might be advantageous to have a directory of all Internet users and their email addresses, but such a directory just doesn't exist.

Here are a few ways to find someone's email address:

Email Etiquette

Writing to someone through email is communicating with another person. You need to remember that the recipient will read it without the benefit of being with you and seeing your expressions or getting your immediate and considerate reactions. You need to say what you mean in a clear, direct, and thoughtful way. Here is a list of rules you should follow when writing email:

Working with Nontext Files

All mail systems can send and receive text (also called ASCII) files-ones that contain only plain characters. In fact, some are designed to do only that. Other types of information such as images, sound, video, programs in the machine language of a computer, spreadsheets, compressed files, or files produced by a word processing program can't be sent or read unless the email program uses some scheme to handle these types of files. On most email systems these nontext files are treated as attachments.  When you're ready to add an attachment, look for an icon in the toolbar or an item in the menu title attachments. Click on it and then give the name of the file to attach. When you're reading email, most email systems represent the attachment as a special icon or some other format. Click on it to view the attachment. If you can't view it in the email program then you'll save it to a file and use another program to view it.

In general terms, before a nontext file is sent it has to be encoded into a form the email program can deal with. In order to read, view, or hear this encoded file, it has to be decoded into its original format. Many email programs, including the one with Netscape, can deal with messages encoded in Multipurpose Internet Mail Extensions (MIME). MIME is becoming the standard way to work with nontext files as part of email or Usenet articles. But there are other programs or formats for encoding and decoding. BinHex has been used on Macintosh systems and with older versions of Eudora, a popular email program. The most common programs for this purpose on Unix systems (and many DOS systems) have been uuencode and uudecode.

When you view a message that's in uuencode or MIME format through the Netscape mailer, the attached encoded file is either displayed in original form or the mail program gives you the option of saving the encoded information in a file. In the later case, it will be decoded and saved in its original format.

Other Email Resources

Here's a brief list of some other resources on the Web that may help you work with and understand email.

This material has been prepared to accompany the book "Searching and Researching on the Internet and the World Wide Web, Third Edition" (ISBN 1887902716) by Ernest Ackermann and Karen Hartman, and published by Franklin, Beedle and Associates, Incorporated, Wilsonville OR, ©2002. No part of this may be reproduced, stored in a retrieval system, or transcribed without permission of the publisher.