One of the very useful things regarding Internet is that it let you almost immediately exchange of electronic message (e-mail) across the entire worlds. On the electronic frontier E-mail is a popular way of communication. You can E-mail to anybody for getting a copy of a selected paper. Electronic mail system provides services which let complex communication & interaction. E-mail provides the following facilities:
- Forming & sending/receiving a message.
- Storing/forwarding/deleting/replying to any message.
- Sending single message to more than one person.
- Sending text, graphics, voice and video.
- Sending a message which interacts with other computer programs.
Another commonly utilized Internet service is electronic mail. E-mail employee an application level protocol called Simple Mail Transfer Protocol or SMTP. SMTP is also a text-based protocol, however unlike HTTP, SMTP is connection oriented. SMTP is also more complex than HTTP.
While you open your mail client to read your e-mail, this is what happens typically:
1. The mail client (Netscape Mail, Microsoft Outlook, Lotus Notes, etc.) opens a connection to its default mail server. Typically the mail server's IP address or domain name is setup when the mail client is installed.
2. The mail server will always transmit the first message to recognize itself.
3. The client will send an SMTP HELLO command to which the server will respond with a 250 HI message.
4. Based on whether the client is sending mail, checking mail etc. the suitable SMTP commands will be sent to the server that will accordingly respond.
5. This request/response transaction will continue till the client sends an SMTP QUIT command. Then the server will say goodbye & the connection will be closed.
Likewise, when you send an e-mail message your computer sends it to an SMTP server. The server forwards it to recipients mail server based on the email address. The received message is hold at the destination mail server till the addressee retrieves it. In order to receive E-mail a user Internet account comprises an electronic mailbox. Any message sent for you is received at your Internet host computer, where it is store up in your electronic mailbox. As soon as you login your Internet account, one of the first things you must do is to check your mailbox.
E-mail system follows client-server approach to transfer messages across the Internet. While a user sends an E-mail message to a program on the sender's computer becomes a client. This contacts an e-mail server program on the recipient's computer & transfers copy of the message. Some of mail programs those exist on Internet are Elm, UCB mail, Pine etc. Though, one thing, which you have to emphasize whereas choosing a mail program, is the user friendliness of that program. However, E-mail on Internet you can be in direct touch of your friend & colleagues.