Jeremy Jaynes of Raleigh was found guilty under a Jerry Kilgore said.that sets limits on the number of e-mails marketers can send in a given time period and prohibits them from using fake e-mail addresses, Virginia Attorney General
Jaynes' sister, Jessica DeGroot, was also found guilty and fined $7,500, Kilgore said. An associate, Richard Rutkowski, was found not guilty.
Jaynes, who used the alias Gaven Stubberfield, was ranked by watchdog group The Spamhaus Project as the eighth-most prolific spammer in the world when he was arrested last December.
The messages sent out by Jaynes advertised penny stocks, low mortgage rates and software to erase Internet browsing records, Virginia officials said. Jaynes sent out more than 100,000 such messages over a 30-day period in July and August 2003 in violation of state law, according to the charges.
DeGroot was convicted after prosecutors proved that she used her credit card to help the operation.
"This is a major victory for Virginians and all Americans," Kilgore said in a statement. Jaynes' attorney was not immediately available for comment.
Although both Jaynes and DeGroot lived in North Carolina, Virginia asserted jurisdiction because they sent messages through server computers located in the state.
Roughly 50 percent of the world's Internet traffic passes through Virginia, home to big Internet companies like MCI and Time Warner's America Online unit.
Many forms of spam are also illegal under a national law that took effect in January.