How Does E-mail Work?

Oversimplifying the process somewhat, e-mail works like this:

1. Using an e-mail program, such as Windows Mail, the sender creates a message and decides who the recipients should be.

2. At a designated place at the beginning of the message, the sender lists the e-mail addresses of all the recipients. (The sender can specify a long list of recipients, but for simplicity, we'll pretend there is only one.) An e-mail address specifies two things: a computer on the Internet on which a recipient receives mail (called an incoming mail server) , and the name that the incoming mail server uses to designate the mailbox of the recipient. So, for example, the e-mail address [e-mail] specifies the incoming mail server whitehouse.gov and a mailbox on whitehouse.gov called president.

3. The sender connects to an outgoing mail server , a computer connected to the Internet (usually a computer owned by the sender's Internet service provider, or ISP) that runs a mail-handling program that supports the Simple Mail Transfer Protocol (SMTP) , which is used for Internet mail). These servers are usually called SMTP servers. The message is sent from the sender's computer to the outgoing mail server.

4. From the outgoing mail server, the message is passed across the Internet to the recipient's incoming mail server.

5. The recipient's incoming mail server files the message in the recipient's mailbox , a file or folder containing all the messages that the recipient hasn't downloaded to her own computer yet.

6. Using an e-mail program (which need not be the same as the one the sender used to create and send the message), the recipient looks for new mail by logging into the incoming mail server. Incoming mail servers use one of three protocols for receiving mail: Post Office Protocol 3 (abbreviated POP3 or POP), Internet Message Access Protocol (IMAP) , or Hypertext Transfer Protocol (HTTP). The incoming mail server uses POP or IMAP to deliver the message to the recipient's computer, along with any other messages that may have arrived since the recipient last checked for mail.

   Note  

   Windows Mail does not support HTTP servers, such as those used for Hotmail If you try to select the option for setting up an HTTP incoming mail server, you see a message to the effect that you must set up a different e-mail type (POP3 or IMAP).

7. The recipient uses the e-mail program to read the message.

Every e-mail message consists of a header (lines containing the address, the return address, the date, and other information about the message) and a body (the text of the message).

Tip  

To send messages right away to people who are logged in at the same time you are, and receive answers in seconds, use an instant messaging program like Windows Messenger (see "Chatting Online with Windows Live Messenger" in Chapter 27).

What Are Attached Files?

Sometimes when you write e-mail, you want to send more than just a message; you want to send files that the recipient can use with an application on her computer. For example, if you are working on a Word document with someone, you don't just want to talk about the document in your e-mail, you want to send revised versions of the document back and forth.

Attached files (or attachments for short) are files that you send along with an e-mail message. The recipient can save the files on their own computer system and/or use them with their own applications. See "Attaching a File to a Message" later in this chapter for directions on how to attach files to e-mail messages.

How Do E-mail Viruses Work?

E-mail viruses are computer viruses-rogue programs that hackers write to do mischief on other people's computers-that spread by e-mailing copies of themselves to other computers. (Technically, such programs are worms , not viruses, but the popular press does not usually make this distinction.) If an e-mail virus gets into your computer, it may try to send infected e-mail to everyone in your address book (Windows Contacts). The e-mail sent will look like it is coming from you-which won't make you popular with the people in your address book.

The most common (but not the only) way for e-mail viruses to spread is through file attachments, especially attachments that are executable (EXE) files or that invoke powerful applications such as Java or ActiveX. The text of the message is a lure to get you to open the attachment. (Remember: the message comes to you from someone who has you in his address book, so it looks like your good friend Bob has sent you a mysterious attachment with a message saying something like "Try this. It's fun.") Once you open the attachment, your computer is infected.

By default, Windows Mail is set up to reduce the number of security problems with incoming messages. However, if you decide to disable security features in Windows Mail, it can be vulnerable to viruses, both because it is widely used and because it can automatically run programs that arrive attached to e-mail messages. To decrease your risk of getting e-mail viruses, see the section "Protecting Yourself from E-mail Viruses" later in this chapter. For more about viruses in general and what you can do to protect your system, see "Protecting Your System from Viruses and Worms" in Chapter 33.

What Are Newsgroups?

Newsgroups provide another way for you to use your computer and the Internet to communicate with the outside world. Newsgroups are called Microsoft Communities by Microsoft. Unlike e-mail, however, a newsgroup is a public medium. When you send a message to a newsgroup, the message is available to anyone who wants to look at it-it's as if you have tacked up a notice on a public bulletin board. You never know who-if anyone -reads your message. The Internet-based system of newsgroups is called Usenet.

Newsgroups are organized by topic. Because there are tens of thousands of newsgroups, topics can be very specific. When you have something to say about the topic of a newsgroup, you can use a newsreading program , such as Windows Mail, to compose a message (which may be many pages or only one line) and send it to your news server , a computer on the Internet that supports the Network News Transfer Protocol (NNTP) , which makes your message available to other news servers. People who want to read the recent contributions to this newsgroup (including your message) can use a newsreading program (not necessarily the same as yours) to download messages from their own news servers.