Microsoft Exchange Server 2003 Distilled

Filtering and Blocking Unwanted E-Mail

Ever since that DEC employee sent the first unsolicited commercial e-mail in May 1978, the spam and e-mail virus problem has been getting worse. Even by the most conservative estimates, spam, junk e-mail, and mal-mail (e-mails that transmit worms, viruses, trojans, and so on) account for nearly 50% of all daily SMTP traffic on the Internet.^[7] In the United States alone, spam accounts for 40% of all e-mail traffic, up from only 8% in 2001. Interestingly, 40% of all mail that flows through the U.S. Postal Service is business marketing mail or what consumers generally refer to as junk mail.

^[7] See the Washington Post article “Spam's Cost to Business Escalates,” March 12, 2003. Available at http://www.washingtonpost.com/ac2/wp-dyn/A17754-2003Mar12 ...