Spam, or unsolicited bulk email, is the posting of emails to large volumes of addresses advertising a service or product which the recipient seldom wants.
Unlike conventional junk mail where the sender pays the cost of postage, recipients of spam pay the transmission costs, either in the form of Internet access fees and/or telephone call charges.
Spam is one of the most significant threats to the Internet, accounting for around 60% of all email traffic. Spam costs consumers and ISPs lots of money in bandwidth charges.
Despite the growing number of technological means for combating spam, the spammers somehow manage to stay one step ahead and the deluge shows little sign of abating.