Section 3 - Email Overview

When you type a letter in an email program (such as Eudora or WebMail) and hit Send, the electronic signal travels over the network or modem connection to the mail server. The mail server then relays the electronic signal out onto the Internet.

The Internet, sometimes called simply "the Net," is a worldwide system of computer networks. Information (such as your email message) is broken into pieces-or packets-which make it easier and faster to transmit. The number of packets that a single message may break into depends on the amount of electronic traffic on the Internet at that time. The email message you sent is reassembled once it reaches the destination mail server. Mail servers are set up for each domain name on a computer network. The servers are the computers that store your mail messages until they are retrieved, read and deleted by an e-mail application. The image below gives you a general idea of how this happens.

1. A user at Computer A generates an email.
2. The email is broken into four packets.
3. Two of the packets are routed to Computer B.
4. The other two packets are routed to Computer C.
5. Computers B and C route the packets to Computer D.
6. Computer D is the final destination computer.
7. The email message is reassembled and read by the recipient.