US ISP EarthLink claimed this week to have won a significant victory against spammers.

EarthLink's policy of pursuing violators of the federal Can-Spam Act through the courts has had significant consequences for Nevada-based internet marketing company KSTM.

A federal judge in Atlanta has awarded the ISP an $11m judgement against KSTM for sending millions of illegal mortgage-related email advertisements nationwide.

"This judgement should be fair warning that if you spam, we will sue," said Larry Slovensky, assistant general counsel at EarthLink.

According to the lawsuit, KSTM sent emails promoting a website known as 'lmlgdnhk.info'. EarthLink claimed that the company used false and misleading header information in its emails which violates the Can-Spam Act.

EarthLink also charged KSTM with breaking the Computer Fraud and Abuse Act, the Georgia Computer Systems Protection Act and state and federal racketeering laws.

The ISP has sued hundreds of spammers since 1996 and won more than $200m in judgements, including two criminal convictions against spammers who received prison sentences for their offences.