Of course, the rise of spam traffic on the Internet has not gone unnoticed by Internet service providers. Many ISP's have instituted some form of spam filtering technology between their customers and the Internet to delete the most obvious forms of spam. These measures are of varying effectiveness, but do help reduce some of the background noise. It's advisable to check up with your ISP to see if they have some form of spam filter working.

In addition, many home Internet Service providers include provisions against sending spam as part of their fair-use agreements for the service. Of course, this is at the discretion of the company, but it is in the interests of a home service provider not to have its members bombarding each other with spam.

Because of this, whole companies are in the business of supplying email services to would-be spam merchants. They provide the Internet access and email servers and the spammer provides the content.

The idea of a national do-not-spam list has been proposed in the United States, but has never really gotten off the ground. This is mainly due to a host of reservations as to how it will affect legitimate online businesses, and the (probably very real) fear that a national list of valid email addresses will simply attract more spam. The latter point illustrates the main problem with legal action vs. spam email senders.

The required operating costs are so low for sending out spam that the people who do it are under no real pressure to operate their businesses legally. This is different from the spammer's closest analog, telemarketing companies. While equally annoying, they need employees and expensive phone lines and equipment to function, meaning they must run a (at least semi-) legitimate business and a national do-not-call list would be effective. No such insurance exits with spammers, and a national do-not-spam list would almost certainly be abused.

How did you get on a spammers mailing list?

Most commercial spam emails are sent using huge lists of email addresses, bought or otherwise acquired by the spammers. It's important to remember that your email address (at least your main one) is a commodity on the Internet. This is why so many sites (especially those offering free services such as software downloads or contests) want your email address. If they have your address they can contact you later, and unless they specifically state that they will not, they can also pass the address on so that others can contact you. In the past, many online businesses have sold their customer lists to raise money or during the process of bankruptcy. If you are prompted for an email address and it does not specifically state that your address will not be used for marketing purposes, be wary. You might well become added to a spammers list.

Of course, there are other ways that commercial spammers can harvest your email address. Automated software tools that search through web pages and record any email addresses that they come across are one method, and equivalent tools are also used to pore through newsgroups in search of useable addresses. For this reason, it is advisable not to display your email address when posting within forums.

One of the most common methods, used by many commercial sites and services on the web is the 'opt-in' box, as first seen in those annoying magazine pullout subscription flyers ('YES!! Please sign me up to receive 12 issues of pet taxidermy monthly and send me my free Elvis bust!').

In the Internet age, these take the form of the ubiquitous set of check boxes at the bottom of the sign up page, pre-checked for you of course, and offering "relevant information from time to time," "great offers from our partners," etc. etc. It all adds up to the potential for unsolicited spam if the vendor is unscrupulous and you are careless with your email address.