The first and probably most important technique for preventing unwanted spam is to simply not give out your e-mail address to any person or business that you do not personally know and trust. This may seem a bit counterproductive to the whole purpose of having an e-mail account, yet it really is the first line of defense in the battle of reducing or eliminating unsolicited e-mail, or simply spam. While it can happen with personal e-mails the sharing or distribution of your e-mail address to sell-able lists typically will occur from the business sector. It is from these sell-able lists that the unwanted spam is born. Try and separate personal e-mail accounts from business related e-mail, which will reduce your personal e-mail exposure to the marketing lists.
Another very helpful strategy for cutting down your spam intake is to have specific e-mail accounts for specific tasks. For example, an e-mail address specifically for public use such as online shopping or signing up for this free trial or that promotion. These public addresses can go ahead and fill up with spam because you don't care. It's not your personal e-mail that has all your private information associated with it. Keep in mind however, when doing any type of online purchase to be cognizant of the privacy policies and how much information you include. There are many companies offering free e-mail services and these are superb for using as a public e-mail.
Finally, even though it does not occur from the private or personal e-mailing sector as often, the sharing of your e-mail address without your knowledge or consent does happen. How does this happen is answered in the information I am about to share with you about how to prevent it. Typically you give your e-mail to a friend and that friend gives it to another. Also, the person you gave your e-mail to is a "feel good" e-mailer, who feels it necessary to send you and all their other friends, co-workers, and acquaintances the joke or 'pass it on' e-mails. In these e-mails they Carbon copied you and everyone else. There it is, your e-mail and 99 other e-mails of people you don't know, some of them business e-mails, who also do not know you but now have a listing of all the included e-mail address. That is how your private e-mail that you only shared with one person has been transmitted around the internet world. So, the technique to prevent this is to very directly and firmly, yet in a nice polite way, inform anyone with whom you share your private or personal e-mail with to not share your e-mail with anyone without first contacting you, and to never include your e-mail in any of their mass mailings. This will prevent any misunderstanding and keep your private e-mail spam free.