LONDON -- BT has launched an automated system to track down and tackle professional spammers and 'botnet'-infected customers on the BT broadband network.

The telco's 'spam buster' system uses content inspection technology from security developer StreamShield Networks to filter spam and virus infected email traffic.

Around 80 per cent of email traffic, equivalent to 6.5 billion messages a day, is junk mail or spam. Increasingly, spammers have taken to using networks of compromised PCs infected by malware and under the control of hackers to distribute spam email. The use of these so-called botnet networks is designed to make it harder to filter email traffic for junk mail simply by blocking rogue email addresses linked to spammers.

BT Group plc (NYSE: BT; London: BTA)