1. Never, ever reply to a spam message. This includes buying a product that is for sale or clicking the often-misunderstood “unsubscribe” link, which actually informs your spammer that you exist. If you can tell from the subject line that a message is spam, don't open it, delete it. Spam subject lines usually promise you a better sex life, a more youthful appearance, prescription drugs without a doctor’s approval, love, thicker hair, or a better mortgage rate. They also use attention-demanding punctuation, such as exclamation marks or all caps.
2. Don’t click any links in a spam e-mail. Spammers often have multiple, unique pages on their sites. Often times, when you click a URL in a spam message, this tells the spammer that you -- and only you -- received the message they sent.
3. Don’t forward an e-mail from someone you don’t know to a list of people. You remember those “forward this e-mail to 20 of your friends” messages? They are perfect for spammers to harvest e-mail addresses, even if the sender of the original e-mail did not have this intent. These types of sign-and-forward e-mails often appear in the form of a petition -- and they don’t work.
4. Don’t use your home or business e-mail address when you register on a Web site or in a group. If you must sign up for services, want to receive more info, register for newspapers or domains; use a free e-mail address from a site like Yahoo to create an address especially for that purpose. This also goes for posting to the Web, in a listserv, newsgroup, on a contact page for a Web site, or on a resume that is posted on the Web.
5. Before you join a list, make sure the list owner or Web master will not sell your address.
6. Preview your messages before you open them. Outlook (and many other e-mail clients) let you use a preview mode to peek at the contents of a message before you actually open it. To do this in Outlook, go the View menu and select Preview Pane. Instead of double clicking a message, click it once to select it and you'll see the message displayed in the Preview Pane.
7.View a message's headers to see if a sender's e-mail address is valid. In Outlook, you can do this by right-clicking the message and selecting Options. (Note that full message headers are usually hidden by default in most e-mail clients.) In the header information you can see if the return address is indeed the address it claims to be.
You can also see information about the servers that passed the e-mail along to you. It may take looking at several headers to get a real feeling of what to look for, but the biggest tip-off is when the return address isn’t the same as the domain of the organization it that claims to be the recipient or if the return address is yours. Spammers usually falsify this information.
8. Use complicated e-mail addresses. Spammers' software will look for the easy and obvious addresses first.
9. Read all your messages as text. That means turning off the ability to view pictures, HTML, movies, and formatted text, which most spam contains).
10. Make sure your privacy settings are set so you don't receive marketing from other sites in your AOL and Yahoo profiles. Many listservs use Yahoo lists as the list provider, you must unselect these pre-selected choices, in your personal privacy settings.
11. Never use your e-mail address as your screen name in chat rooms. It will give spiders or human e-mail harvesters an absolute yes to a questionable e-mail address.
12. Don’t give your real address to a Web site for registration. If you must register with a real e-mail address, make sure you can opt out of receiving unsolicited e-mail from the site where you're registering. If you are unsure about this, read the site's privacy statement.