How They Work

How Emails Work – Part I Just a couple of days ago, the world was rudely awakened by the news that, the Icon behind the Apple, MAC and iPhone, Steve Jobs, CEO and co-founder of Apple had passed away. This is really a big blow to the industry where his brains had brought about tremendous change. Surely, we shall all miss Steve Job’s innovations. May God grant him Eternal Peace, Amen. The other day, I received a phone call from a friend of mine doing his master’s degree; he had been asked to write a paper on what “E-Mail” is and when did it start. Then, I realised that, though there are many people using this facility worldwide, only a few may understand well how it works and what it is all about. Every day, hordes of people on the Internet send each other billions of e-mail messages. You may have sent a dozen or more e-mails each day without even thinking about it. Visibly, e-mail has become an extremely popular communication tool. Have you ever wondered how e-mail gets from your computer to a friend on the other side of this planet earth? What is a POP3 server, and how does it hold your mail? It may be surprising to know, because it turns out that e-mail is an incredibly simple system! First and foremost, when did this whole thing start? According to Darwin Magazine, Prime Movers, the first e-mail message was sent in 1971 by an engineer, Ray Tomlinson. Before this, it was only possible to send messages to users on the same computer or device. Tomlinson’s breakthrough was the ability to send messages to other machines on the Internet, using the @ sign to designate the receiving machine. An E-mail message is nothing more than a simple text message or a piece of text sent to a recipient. Even now, an e-mail message tends to be short pieces of text, although the ability to add attachments now makes many messages quite long. Even with attachments, however, e-mail messages continue to be text messages. The E-mail Clients - Most probably, you may have already received several e-mail messages today or in the near past. To look at them, you use some sort of e-mail client. Many people use well-known, stand-alone clients like Microsoft Outlook, Outlook Express, Eudora or Entourage. Some people who subscribe to free e-mail services like Hotmail or Yahoo use an e-mail client that are embedded in a Web page. No matter which type of client you’re using, it generally does four things: - • Shows you a list of all of the messages in your mailbox by displaying the message headers. The header shows you who sent the mail, the subject of the mail and may also show the time and date of the message and the message size. • Let’s you select a message header and read the body of the e-mail message. • Let’s you create new messages and send them. You type in the e-mail address of the recipient and the subject for the message, and then type the body of the message. • Let’s you add attachments to messages you send and save the attachments from messages you receive. More Sophisticated e-mail clients may have a horde of many bells and whistles, but at the core, this is all that an e-mail client does. In order for E-Mails to work, one requires a sort of E-mail Server, it is this that will receive and send the mails to the relevant E-Mail accounts. This works in the same way your local Post Office does! Given that you have an e-mail client on your machine, you are ready to send and receive e-mail. All that you need is an e-mail server for the client to connect to. Let’s imagine what the simplest possible e-mail server would look like in order to get a basic understanding of the process. There are Web servers, FTP servers, telnet servers and e-mail servers running on millions of machines on the Internet right now. These applications run all the time on the server machine and they listen to specific ports, waiting for people or programs to attach to the port. (To be continued) Eddie@afrowebs.com