Understanding the Sending and Receiving Process

Email (Electronic mail) works in a very similar fashion to standard mail, and so in order to explain the components of email and how they fit together we are going to first review the current postal or snail mail system, and as we do will introduce the email equivalent.

It starts with you writing a letter. The letter contains your message. Once you have finished your letter you place it in an envelope and the write the name and address of the person/business you are sending the letter to on the envelope.

You then take the letter to a post box. This can be any post box and you post it. As far as you are concerned it is .. job done. You now rely on the mail system to deliver your letter to the destination.

In the email world a very similar process occurs.

To write your letter you use a pen and paper. In email you use an email client (like Outlook Express). The email client provides you with a message form similar to the one below:

You should note that the message form consists of two main parts.

 The top part is the addressing; which is equivalent to the envelope of a standard letter, and the bottom half is for the message content; which is the equivalent to the letter itself.

Once you have finished you click send which sends the message on its way. It is the equivalent of you posting the letter.

To post a letter you need to find a post box. Any post box will do, it could on your street or in a shopping centre- it makes no difference.

Once your letter is in the post box it is in the postal system and the rest is for the postal workers to worry about.

In the email world pressing send transfers the message ( a copy)  from your computer to a messaging computer on the Internet. Once that transfer is complete the message is effectively "Posted" and is in the email system.

However for that to occur you have to configure your email client with information about the computer that will receive the message .i.e. the location of the post box.

The message transfer uses a protocol called SMTP and the computer that receives this message is known as the SMTP server.

In the early days of the internet you could use any SMTP server to send your email, just as in the postal world you can post your letter in any post box.

However because of spam  restrictions are now common and you must have permission to use the SMTP server in order to send email using it.

Note: Configuration details will be considered later.

Message in Transit

Just as you don't know how your letter gets from you local post box to a post office near to the house/business of the intended recipient you don't need to know how email does it either and so I won't cover it here.

Message Delivery

In the UK the final part of the letter delivery is done by a local postman who brings the mail direct to the house and it is probably the same in most countries.

However if you have ever lived in a communal building (apartments )then you will be familiar with post boxes.

The idea is rather than the mailman going to each apartment/room/office in a building he puts it in a post box in central location.

So how do you know if you have a letter?... You have to go to your post box and check!

As you can see from the picture there can be 100s of boxes. So which one is yours?...It has your name on it!

The reason I emphasise the above is that the distinction is important. Your aren't told... you have to check!

In electronic mail emails destined to you are placed on an email server that belongs to your email provider.

The job of checking if there are any emails for you is done by your email client. You can tell the email client to check periodically and you can tell it to check at any time by using the send/receive button.

It is important to note that the client isn't told that you have messages it must contact the email server and ask!

To do that the client uses a protocol called POP3 (post office protocol version 3) (note: IMAP4 is sometimes used).

For this to work your client needs to be configured with the address of your email providers email server (pop3  server) and your email account details- name and password.

The screen shot shows typical configuration for incoming/outgoing email servers. You should note that these are given to you by your email provider.