Once the spam filters learn of a spammer they block them.
But quite a lot of people have to suffer from their spam activity first.

I remember Steven Fry on QI asking what the bulk of internet traffic was and the answer was over 90% spam.

So if there was a solution I think someone would have become a billionaire with it by now.You know that old saying “there is nothing certain in life but death and taxes”?

I think we need it revised for the 21st century to

“there is nothing certain in life but death, taxes and spam email”

While there are numerous spam filters available, nothing really works 100% all the time, and any spam filter comes with the risk that you will potentially delete emails from new customers, there are some things you can do when spam gets overwhelming.

These are some useful suggestions that are worth knowing about:

1. Take advantage of the Junk E-mail Filter in your email software which automatically evaluates incoming messages and sends those identified as spam to the Junk E-mail folder.
2. Use you “block sender” option to block any further emails from a sender.
3. Block pictures in HTML messages that spammers use as Web beacons. By default, this feature blocks automatic picture downloads and other external content in messages if the content is linked to a server. If you open a message that has external content when this feature is turned off, the external content downloads automatically, inadvertently verifying to the server that your e-mail address is a valid one. Your e-mail address can then be sold to a spammer. You can unblock external content for messages that come from sources that you trust.
4. Turn off “read and delivery receipts” and automatic processing of meeting requests. Spammers sometimes resort to sending meeting requests and messages that include requests for read and delivery receipts. Responding to such meeting requests and read receipts might help spammers to verify your e-mail address. You can turn off this functionality.
5. Limit the places where you post your e-mail address. We all need our email addresses on our web sites, but unfortunately whenever you list or link to your e-mail address, you increase your chances of being spammed.
6. Review the privacy policies of web sites and only join those you need and trust such as online banking, shopping, or newsletters. Look for a link or section (usually at the bottom of the Web site’s home page) called “Privacy Statement,” “Privacy Policy,” “Terms and Conditions,” or “Terms of Use.” If the Web site does not explain how your personal information will be used, consider not using the services at that site.
7. Watch out for check boxes that are already selected. When you shop online, companies sometimes add a check box that is already selected, which indicates that it is fine with you if the company sells or gives your e-mail address to other businesses (or “third parties”). Clear this check box so that your e-mail address is not shared.
8. Don’t EVER reply to spam. Never reply to a spam e-mail message — not even to unsubscribe from a mailing list. Answering spam just confirms to the spammer that your e-mail address is an active one.
9. If a company uses e-mail messages to ask for personal information, don’t respond by sending a message. Legitimate companies will not ask for personal information to be sent in e-mail, so be very suspicious if they do. Such a request could be a spoofed e-mail message disguised to look like a legitimate one. This tactic is known as phishing.
   If the possible spam appears to be sent by a company that you do business with — for example, your credit card company — then call the company to verify that they sent it, but don’t use any phone number that is provided in the e-mail. Instead, use a number that you find by using other means, such as directory assistance, a statement, or a bill. If the request is a legitimate one, the company’s customer service representative should be able to assist you. The Junk E-mail Filter also includes phishing protection to help identify and disable suspicious messages.
10. Don’t contribute to a charity in response to a request sent in e-mail. Sadly, some spammers prey on your goodwill. If you receive an e-mail appeal from a charity, treat it as spam. If the charity is one that you want to support, locate their telephone number or Web site to find out how you can make a contribution.
11. Don’t forward chain e-mail messages. apart from the fact that by forwarding a chain e-mail message you might be furthering a hoax, you also lose control over who sees your e-mail address.