Electronic Mail (E-mail)

Introduction

E-mail abbreviation electronic mail, message transmitted and received by digital computer through a network, LAN (Local Area Network) or WAN (Wide Area Network). An e-mail system allows computer users on a network to send text, graphics and sometimes sounds and animated images or movies to other users.

On most networks, data can be simultaneously sent to a universal of users or to a select group or individual. Network users typically have an electronics mailbox that receives, store and manage their correspondence. Recipients can select to view, print, save, edit, answer or reply, forward, delete and otherwise react to communication. Many e-mail systems have privacy features. Large corporation and college use e-mail system as an important communication link among employees and other people allowed on their networks. E-mail is also available on major public on-line, many of them maintain free or low-cost global communication networks.

The Nature of E-mail System

The e-mail is the most important Internet resource; it acts as the transport agent on the Internet. Every day, countless messages are sent from one part of the Internet to another. However, the e-mail system is a general service that can transport all types of information: documents, publications, computer program, any types of files and so on. The only requirement is that the data be stored as ASCII characters, that's mean the data uses the regular set of characters that are on our keyboard and readable. One of the most significant uses of this e-mail is to allow people who are not near one another to work together on a project. Indeed, it is common for someone to collaborate with a person who is thousand of miles far or inch nearest, someone they will never actually meet in person.

For example, as this report was being written in Penang, each part was sent to a person in Petaling Jaya and a person in United Kingdom, both of whom would review the work and make comments. The text of the report was sent as a mail message. Each reviewer would insert his comment right into the text and main it back. Because the Internet is so fast and reliable, it was not uncommon for us to be able to review an entire part within a day. If we had to depend on post office mail, the whole process would take few weeks.

The same process is carried out, on a much larger scale, when decision have to be made that affect the Internet itself. A new idea or a new standard is proposed after which anyone can participate in a worldwide debate via the mail system.

The Internet connects thousand of different network, each of which has its own mix of computers and software. How can all these different system work together to exchange mail?

The absolute answer is that the delivery of mail is standardized by a system called SMTP. SMTP stand for Simple Mail Transfer Protocol, its part of the TCP/IP (Transmit Control Protocol / Internet Protocol) family of protocols. It describes the format of a mail message and how message is handled as they are delivered. Every Internet computer runs a mail program that works behind the services to ensure that message are addressed and transported in an orderly fashion. This program called a transport agent, follows the SMTP protocol and in doing so, provides your mail link to the outside world.

On most system, the transport agent runs by itself in the "background", always ready to respond to whatever request it may receive. In UNIX terminology, such program calls a daemon.

Every UNIX system has various daemons that are working in the background, quietly providing services for you. In theory, it doesn't matter what transport agent your system uses as long as it knows how to send and receiving mail using SMTP. Most UNIX system uses a daemon named send mail.

What we do want to summarize of this part is that the mail system works because everybody's network has at least one computer running a transport agent that sends and receives mail according to the SMTP standard.

The Interface to the E-mail System

As a user, we do not interact with your system's transport agent; it operates behind the scenes sending and receiving mail via SMTP. The mail program that you use called a user agent. It is the user agent that acts as your interface into the Internet. E-mail system, allowing you to read your messages, composed new messages, delete message that you have already read and reply.

The most widely available user agent is the UNIX mail program. This program comes with all UNIX system and hence is available to most Internet users. For the common knowledge, the first version of mail was primitive only provide two functions, there are composing and read messages. Some years ago, the newer versions of mail were developed that are more powerful.

E-mail Program

Pegasus, also call P-mail, is a user agent for Local Area Network (LAN). However, Pegasus developed by David Harris of Dunedin, New Zealand. P-mail distributed free over the Internet and does not require Novell's MHS software (Message Handing Service).

SMTP when they send and receive mail, SMTP will describe how messages are to be handled. For network that have many Personal Computer, there is another protocol that is sometimes used named POP (Post Office Protocol). This Personal Computer can run a special POP based user agent that takes advantages of this protocol.

Within each Internet sites, there are more than one computer that act as mail repositories. Messages that are waiting to be read are kept on this computer; they are sent to your personal computer where they are stored until read the mail.

To see how this works, imagine a message is being sent to you from the other side of the world. At each step along the way, the messages sent from computer to computer over the Internet. Eventually, the messages arrive at the computer in your network that acts as a mail repository.

Simple Mail Transfer Protocol is the standard TCP/IP mail protocol, when message travels through the Internet, the last leg of its journey, the message is sent to you PC using the POP protocol.

Post Office Protocol based user agent has certain important advantages. First, they give you complete control over your mail, because message are stored on your personal computer, that's mean you can keep a lot of message without having system manager complaint that your message are taking up too much disk space.

Some of the common POP based user agent that you may used are Eudora, Nupop and Popmail, beside that its also best for people who are use only one PC that they do not have to share.

Basic Terminology

In this E-mail terminology, the mail mean's electronic mail and address mean's e-mail address. Beside that, the snail mail mean's the post office mail.

After you read a message, there are several ways to dispose of it. First you can get rid of the message, then deleting it. While you are still within the mail program, it's usually possible to get back a deleted message. However, once you quit the program, the entire deleted message is gone for good.

Beside that, it the messages requires an answer, you can reply to it. Your mail program will make it easy for you to send a response back to the same use rid that sent the original message. If you want, you can even include parts of the original message in your response as a refer to the sender.

Another option is to save a message. This means the contents of the message are copied to a file that you can keep as long as you want. You may also choose to forward a message. The mail program will make a copy of the message and send it to whomever you specify.

When you send a message, you specify the use rid of the recipient. At the same time, you can specify more than one recipient and the message will be sent to each other, You can also designate one or more use rid to receive copies of the message. There are two types of copies; BCC and CC. Normally, each recipient will see the name of all the other use rid who were sent a copy of the message. A blind copy is a secret copy, that any one else doesn't know about. When you receive a message, there is no way for you to tell is a blind copy was sent to someone else.

As the name implies, this is mailing list of use rid who are all to receive the main. Mailing lists can be quite large and will have some person who acts as an administrator. Within the Internet, there is literally thousand of different mailing list devoted to different subject areas.

Even more important, do not assume that mail is private. Although you may send what you think is a private message, it is way for the recipient to send a copy to someone else, and you will have no way of knowing what has happened.