Nearly 95 percent of the email sent in 2007 has been "spam," junk advertising loathed by its recipients, according to a report released on Wednesday by a US web security firm.
The amount of junk email has skyrocketed despite a 2004 US CAN-SPAM Act that placed restrictions on sending unwanted messages and sanctioned penalties for "spammers," according to California-based Barracuda Networks.
Junk messages made up an estimated 70 percent of email the year the act was passed, the Barracuda report indicates.
"The spam war is a continuous battle between spammers and security vendors," said Barracuda chief executive Dean Drako.
"Security vendors now require 24-by-7 defence operations to continuously monitor the Internet for new spam trends and distribute new defensive solutions immediately."
Barracuda said it based its findings on analysis of more than a billion email messages received daily by its approximately 50 000 customers worldwide.
Spammers cunningly hide their identities by routing emails through other people's websites, blogs or computers, according to Barracuda.