So little time. Email is an internet service that allows users to easily send text messages to each other across networks. It allows millions of users to pass message without even thinking about how it gets to the destination computer. Email is routed from computer to computer by way of an email address. This address is unique to every users on the internet.
Email is nothing more than text.
Different email servers process this text to route the email from you to your recipient. You write an email on your computer using an Email Client such as Outlook Express or Netscape Messenger. The SMTP server adds some information to the message and begins it on its way. That user opens their email client and it connects to that POP3 server and downloads the messages, finally presenting them to the end user. Depending on the bandwidth along the way and the load on the servers this can take anywhere from a few seconds to hours.