Email Spam

E-mail spam, also known as junk e-mail, is a subset of spam that involves nearly identical messages sent to numerous recipients by e-mail. A common synonym for spam is unsolicited bulk e-mail (UBE). Definitions of spam usually include the aspects that email is unsolicited and sent in bulk. "UCE" refers specifically to unsolicited commercial e-mail.

E-mail spam has steadily grown since the early 1990s. Botnets, networks of virus-infected computers, are used to send about 80% of spam. Since the cost of the spam is borne mostly by the recipient, it is effectively postage due advertising.