Email is a method of sending messages, voice, video, and graphics over a digital communication link such as the Internet anywhere in the world at a very cost-effective rate. Technically, email is a type of client/server application that provides a routed, stored message service between any two email accounts. Because all modern computers can be connected o the internet, users can send emails over the internet to any location that has a telephone or wireless digital service.

Introduction to Email | Electronic Mail

The backbone of an electronic mail system is a communications network that connects remote terminals to a central system or a local area network that interconnects personal computers. users can send mail to a single recipient or they can broadcast it to any number of selected users on the system.

There are two broad procedures available for email.
  1. Subscribe to email services such as Hotmail, rediffmail, etc.
  2. Install your own email server on the Internet.

The first option is not advisable for business setup due to the following reasons:
  1. Email belonging to your business may be carrying someone else's advertisement.
  2. Your name might be used by someone else. it means that your mail is not safe it can fall in the wrong hands.

However, the following are some advantage of using this method:
  1. Administering your own email setup is avoided.
  2. When the number of messages is small, an exclusive setup for email is not cost-effective.
  3. Your email address does not identify you. so it may not be easy for the sender to locate you and thus you are saved from receiving junk or useless mail called spam.

Advantages of setting up your own email server are:
  1. you can host your Web pages as well as run your mail server.
  2. The initial cost of setting up your own mail server may be high but as the volume of email messages increases, the overheads may not go up. Therefore, the price you pay per message will come down.

E-Mail networks and servers

The primary component of the electronic mail system is a "post office", an area on the shared hard disk that is reserved for mail. this post office serves as the central message holder and has both 'in' and 'out' baskets for each user. to send a message, a link is established between the sender's 'out' basket and the addresses 'in' basket.

The method for receiving mail depends on the sophistication of the system. When multitasking personal computers and workstations are used, mail can be delivered to users while they are working on something else. Otherwise, users have to interrogate their mailboxes (disk space) in a central system or file server.

Electronic mail programs often come with local area network software or as add-on options. or, they may be independent programs designed to work with a particular network environment.

How Email works on the Internet.

Email is the most heavily used feature of the Internet. you can use it to send messages to anyone who is connected to the internet or connected to a computer network that has a connection to the Internet, such as an online service. Email messages are sent in the same way as most internet data. the TCP protocol breaks your messages into packets, the IP protocol breaks the packets to the proper location, and then TCP reassembles the message on the receiving end so that it can be read.

You can also attach binary files, such as pictures, videos, sound, and executable files to your email messages. Because the internet is not able to directly handle binary files in email, the file first must be encoded in one of a variety of encoding schemes. popular schemes are MIME and uuencode. The person who receives the attached binary file (called an attachment) must decode the file with the same scheme that was used to encode the file. many email software packages do this automatically.

When you send an email to someone on the Internet, that message has to travel through a series of networks before it reaches the recipient. different networks might use different email formats. gateways perform the job of translating email formats from one network to another so that the messages can make their way through all the networks of the Internet.

List Server

A list server is an automatic mailing system available on the internet. Rather than sending an email on a particular topic to a long list of people individually, you send it to a special email address, where a program automatically distributes the email to all the peoples who subscribe to the mailing list.

A mailing list is one of the most exciting uses of email. It connects a group of people who are interested in the same topic, such as homeschooling. when one person sends an email to the mailing list, the same is also sent to everyone on the mailing list.

When you want to subscribe to a mailing list, you send a message to a computer instead of a person. that computer, known as a list server, reads your email and automatically subscribes you to the list. you can unsubscribe to the list in the same way.

A mail reflector is a program that runs on an Internet computer and routes mail to members of a mailing list. in a different kind of mailing list known as a list server, you subscribe to a mailing list by sending it to your email address. you will get every message that everyone sends to the list. in yet another kind of email mailing list, you can subscribe to, you only receive mail that a single person sends, only that person can send to the list. Mostly, electronic newsletters are distributed in this way.

Listserv commands that used to send the email.

  1. help - Sends back a summary of basic commands.
  2. info? - sends back a list of available topics.
  3. info topic - sends back information on the specified topic.
  4. review list - sends back information on the specified list.
  5. setlist ack - sends a confirmation message for the specific list.
  6. setlist Noack - Does not send a confirmation message for the specified list.
  7. setlist mail - Begins mail deliveries from the list.
  8. setlist nomail - Stops mail deliveries from the list.
  9. setlist repro - Sends copies of your own message.
  10. setlist norepro - Do not send copies of your own message.
  11. subscribe list - Opens a subscription to list.
  12. your-name signup list - opens a subscription to the list.
  13. signup list your name - Register a subscription to the list.
  14. unsubscribe list your-name - Cancels a subscription to list.
  15. signoff list - Cancels a registration to list.

To issue one of these commands, send an email to the list server address, leaving the subject line blank, and include one command as the body of the message. Do not add a signature file.

Relatively simple programs in the client and server will use the Post Office Protocol version 3 (POP3) to move email from the server to the client. the server does not retain email from the server to the client. The server does not retain email after it is transferred, so it is difficult for a user to keep track of email using different computers.

Sophisticated programs in the client and server use the Internet Messaging Access Protocol Version 4 (IMAP4). this software can control the transmission of large files or specialized mail, like voice annotated text, move email from the server to the client. the IMAP4 server retains a replicated set of the files, so it is easy for a user to keep track of email using different client computers.

An email server at an Internet Service Provider (ISP) exchanges with other servers throughout the Internet using the Simple Mail Transfer Protocol.