Apart from defining the term spam, this chapter has shown that there are true financial rewards for spammers, and that the costs to market via spam email are very low for the spammer. However, they affect the recipient of the email to a large extent.

Spam has been a part of the Internet for a long time, even before the World Wide Web took roots, and despite legislation, it will probably continue to be a problem in the future. Even if one country had a truly solid anti-spam law, the global nature of the Internet implies that spam could still arrive from an overseas source.

As the use of email increases, both for business and personal use, and as the ratio of spam increases still further, it is important for companies to filter out spam to preserve efficient operations. SpamAssassin is a spam-tagging tool that can provide very effective filtering capabilities when configured correctly. This book will describe how to install, configure, and maintain SpamAssassin to provide an effective anti-spam solution.