I only know of two sure ways to avoid spam altogether:

(1) Stop using email
      or
(2) Use a "safe list" (a.k.a. "white list") that will only accept email from certain addresses.

In Outlook Express you can do this by clicking on Tools>Message Rules>Mail, and following the prompts to list the email addresses you will accept mail from.

Do this in Outlook by going to Tools>Rules & Alerts>E-mail Rules>New Rule and following the prompts to list the email addresses you will accept mail from.

Alternatives

Other than the steps above, the quickest and most reliable way to stop spam from arriving in your Inbox, is to change your email address.

Once your email address (screen name) is on a spam list it will never come off, unless the spammer just plain goes out of business. This the way things are, despite a federal law having been passed against distributing unsolicited email. (The law has proven to be unenforceable — which many of us predicted would be the case.)

Yes, I realize that giving up a name you really like (such as, say, JohnQDoe@xyz.com) is not an easy decision to make. However, you can check to see if the name is available at one or more of the various free web-based email services, such as Gmail, Hotmail, Yahoo, Juno, or AIM. YourName@gmail.com may be available at www.google.com just waiting to be snapped up.

There are other advantages to using a web-based service, even if your current email address is not being swamped with spam. But first, let's look at what spam is and why your current screen name is pretty much stuck with it.

Spam Makes Money for the Spammers

Sending out millions of spam-laden emails is a relatively cheap way to make some easy money. Think about it: If you had a mail-order item to sell, which would be more practical — buying paper, ink, envelopes, and postage stamps (not to mention the cost of printing the ads and stuffing the envelopes) or spending a few minutes at your computer to accomplish the same thing?

So how do spammers make money when you, personally, never click on the links or attachments they send you? Well, even though you don't, many people do. If spam didn't pay off, spammers would stop sending it.

And it's cheap for a spammer to "fill an order" once he is given a credit card number or sent a check. Many of them give you nothing — they literally take your money and run. Why not? They know it's virtually impossible to track them down or take them to court.

And how much effort would you put into trying to get back the $20 you were conned out of? Most victims are too embarrassed to admit they were scammed.

Of course some scams can take you for thousands of dollars — but, again, it is nearly impossible to track down the culprits who stole your identity and emptied your bank account. In fact, many of them operate out of foreign countries, including Russia and China.

Why Can't Spam Be Stopped Before It Gets to My Inbox?

Well, for years the industry's argument was "Would you expect your letter-carrier to sort through your mail each day and weed out all the advertising before putting anything in your mailbox?"

After all, your postman can't see what's inside each envelope — however, the various email services can see what's in the messages they handle. As a result, they finally decided to try filtering out the unwanted stuff before it gets to you.

No Filtering System Is Perfect

Sooner or later, a piece of spam will get through because it somehow looked like a legitimate message. Conversely, a legitimate message may look like spam and be blocked. Nonetheless, most email services now do their best to spot advertising and set it aside in a folder marked Spam or Junk, whereupon you can easily check it out and delete it.

Gmail

My favorite email service has become Gmail (Google mail) because it appears to do the most accurate job of filtering. And Google makes it easy to remove stuff from its Spam folder in one fell swoop by clicking "Delete All Spam Messages Now."

Getting back to avoiding junk email, changing your email address will instantly stop any you are currently receiving — but it is no guarantee that you won't end up on one or more spam lists in the future.

How Do Spammers Get Our Email Addresses?

There are many ways. If your email address appears on a website there is a good chance it will be found by automated "harvesting" programs.

Likewise, if your screen name is printed on stationery or a business card it may be found and used against you.

Beyond these resources, spammers will type out thousands of "likely" screen names such as, say, bobjones@aol.com, bobjones@hotmail.com, bobjones@comcast.net, ad infinitum. They couldn't care less about how many of them bounce — they are working on percentages, and the more emails they send out, the more likely they are to find a customer.

Funny Story (Fw, Fw, Fw...)

Another source of email addresses for a spammer is chancing upon a list of "Forwards" that have been included with a cute story or a joke of some kind. All these addresses show up because the sender had put them into the Carbon Copy field instead of the Blind Carbon Copy field.

Had the names been included as BCCs, rather than CCs, only your own address would be displayed on the copy you receive. Likewise, all the other recipients would see only their address on their individual copies.

Yes, of course I understand that none of your friends would sell all these email addresses to a spammer, but when dozens of these forwarded and re-forwarded emails are in circulation there is no telling whose hands they may fall into.

Therefore, stop using the CC field and always use the BCC field — and please tell all your friends to do the same!

What About Commercial "Anti-Spam" Services?

Well, if you don't mind paying for the same kind of filtering you can get for free from Gmail, go ahead and try them out. Be aware, however, that these programs use your system resources to monitor each piece of email you receive. This can slow down your computer noticeably. Google and the other free web-based services use their own resources to filter all messages before they ever get to you.