"This is a historic victory in the fight against online crime," said Bob McDonnell, Virginia's Attorney General.

"Spam not only clogs e-mail inboxes and destroys productivity -- it also defrauds citizens and threatens the online revolution that is so critical to Virginia's economic prosperity."

Jeremy Jaynes was one of the world's most prolific spammers -- he is thought to have made millions of dollars in revenue from sending unsolicited bulk e-mail.

His lucrative trade came to an end when Virginia prosecutors took advantage of the fact that his e-mails transited via a server located in the state, operated by AOL.

Jaynes was sentenced in 2004 to nine years in jail for violating the Virginia Anti-Spam Act.

He has been under house arrest during the appeal process -- Jaynes hoped that his e-mails would be protected as free speech under the US constitution.

But the state's Supreme Court took the opposite view in a 4-3 decision, ruling that commercial material was not covered by the constitution.

The dissenters on the Supreme Court's panel took a different position, stating that the decision sets a difficult precedent.

Justice Elizabeth Lacy claimed that the Virginia Anti-Spam Act was 'unconstitutionally overbroad on its face, because it prohibits the anonymous transmission of all unsolicited bulk e-mail including those containing political, religious or other speech protected by the First Amendment to the United States constitution.'

Jaynes' defence took consolation from the dissenting opinion.

"Unfortunately, the state that gave birth to the First Amendment has, with this ruling, diminished that freedom for all of us," said Thomas Wolf, the lawyer representing Jaynes in court.

"As three justices pointed out in dissent, the majority's decision will have far reaching consequences."

"The statute criminalises sending bulk anonymous e-mail, even for the purpose of petitioning the government or promoting religion."

Jon Praed, a lawyer with Internet Law Group, described the ruling as 'groundbreaking.'

"Before this case, the only spammers who had been convicted were convicted of things that were crimes without reference to their spamming activity," he said.

"It was important to establish that spam is illegal because it's unsolicited bulk commercial e-mail -- without regard to the quality of the content that you're advertising."

Jaynes' case may now go up for appeal before the US Supreme Court, according to his lawyer.

"We are going to study these lengthy opinions, but I don't see us giving up on these important constitutional issues," said Wolf.