Every time you give your e-mail address to a Web site, you risk the chance that it will be sold to a rabid spam monger. You can reduce this risk by using disposable e-mail addresses (DEAs). Such addresses are generally provided by a paid service company that forwards mail from a DEA to your actual address. In general, you name the DEA so it can identify the recipient. If you start getting spam on a particular DEA, you know which recipient to blame, and you can terminate that DEA and report the abuse. We reviewed five such services in "Slam the Spam".

Depending on the way your e-mail is handled, you may be able to create your own DEAs without paying for the service. Many e-mail servers ignore certain additional characters in e-mail addresses and deliver the messages regardless. You can use this bit of information to your advantage.

The only way to find out whether this will work is to try it. Ask a friend to send you two e-mail messages using modified versions of your e-mail address. For one, insert a plus sign (+) and a word (with no spaces) before the @ sign. For the other, insert a word in parentheses. For example, if your address is nobody@nowhere.com, you could specify one address as nobody+monkey@nowhere.com and the other as nobody(monkey)@nowhere.com.

Once the messages are sent, check your e-mail. If either message reaches your in-box, it means you can create DEAs using the format that succeeded. When you place an order with www.whatever.com, insert +whatever or (whatever) in the e-mail address you submit. If you begin to get spam on that address, use your e-mail client's message rules to delete messages with that address in the To: field.

Sure, a human could extract your real address from this poor man's DEA at a glance, but spam mongers don't spend time looking at individual addresses. Of course, if you want a greater degree of separation from your DEAs, you can use one of the subscription services.