The document discusses spam emails and anti-spam techniques. It defines spam emails, describes how spammers earn money and send spam emails. It also discusses the costs of spam emails, various types of spam like email spam, chat spam and search engine spam. The document then covers techniques used by individuals, email administrators and email senders to prevent spam emails. These include filtering, blocking, authentication and legal enforcement. The conclusion states that no single technique can fully solve the spam problem and both users and administrators need to use different anti-spam methods.

22. THANKYOU