A court in Virginia has struck down a spammer's appeal that his conviction violated his rights to free speech.

Jeremy Jaynes was named as one of the world's top 10 spammers in 2003 by watchdog Spamhaus, and was estimated by prosecutors to be pumping out 10 million emails a day netting him $750,000 per month.

Jaynes was convicted in 2004 of sending unsolicited emails with forged headers and sentenced to nine years in prison. He remains free on $1m bail and his last attempt to evade jail is an appeal to the US Supreme Court.

"This is an historic victory in the fight against online crime," said Virginia State Attorney General Bob McDonnell.

"Spam clogs email inboxes, destroys productivity, defrauds citizens and threatens the online revolution that is so critical to Virginia's economic prosperity."

However, the vote was very close as four judges voted for rejection and three opposed.

Justice Elizabeth Lacy wrote in a ruling that the law is "unconstitutionally overbroad because it prohibits the anonymous transmission of all unsolicited bulk email including those containing political, religious or other speech protected by the First Amendment to the US Constitution".