A North Carolina man and his two confederates illegally flooded America Online e-mail accounts in July 2003 with millions of advertisements hawking penny stocks and work-from-home schemes, Virginia prosecutors told jurors yesterday.

Jeremy Jaynes, his sister Jessica DeGroot and Richard Rutkowski, all of Raleigh, N.C., are on trial in Circuit Court in Loudoun County, where America Online is based, on charges of violating a Virginia anti-spam law that took effect last year. If convicted, each could face up to 15 years in prison and $2,500 fines.

Prosecutors have said the trial is the nation's first felony prosecution of spammers. It could point the way for future litigation in the fight against spam, which experts say accounts for more than 70 percent of e-mails and costs businesses $10 billion a year.

In their opening statements, defense attorneys said Internet marketing does not violate what they called a poorly written law.

As routers, a server and stacks of computer discs were tagged as evidence, attorneys on both sides tried to simplify for jurors the elements of a case fraught with ultra-technical language.

Russell E. McGuire, a prosecutor in Virginia's attorney general's office, said the defendants violated state law by disguising themselves and their location to send unsolicited bulk e-mails, or spam, through a server in Loudoun.

McGuire said they used falsified or forged return Internet addresses on their e-mail ads. Spammers do that to elude authorities and ignore recipients' requests to be removed from mailing lists.

McGuire depicted Jaynes as the leader of a spam operation run out of his home. Jaynes's bank accounts recorded regular deposits of $39.95, he said -- the price of the products the defendants allegedly pitched.

McGuire said that a credit card issued to DeGroot was used in the scheme and that Jaynes paid her thousands of dollars each month. Rutkowski opened a mailbox to which one of the defendants' fake companies was registered, he said.

Jaynes's attorney, David Oblon, dissected the language of the statute to indicate that Jaynes did not violate all its elements.The law "is a poorly written, complicated statute," he said. "It is very difficult . . . to prove a violation."

Leo Andrews, Rutkowski's attorney, said the accusations did not amount to criminal behavior. Thomas Mulrine, DeGroot's attorney, said there was no evidence that she used her credit card to participate in a spam business or that any e-mails the defendants might have sent were unsolicited -- the word that transforms bulk e-mail advertising into spam. "Marketing via the Internet is not a crime," Mulrine said. "It may be annoying to you. . . . It is not a crime."

When he was indicted in December, Jaynes -- under the name Gaven Stubberfield -- was listed as the world's eighth-worst spammer by Spamhaus.org, a spam tracking organization.

The felony indictment alleges that the defendants sent more than 10,000 spam e-mails on three dates in July 2003. On Monday, prosecutors dropped a fourth felony count.

When it was passed, the Virginia law was touted as one of the nation's toughest anti-spam statutes. Since then, many states, including Maryland, have passed similar legislation. A federal anti-spam law took effect in January.

In the past, spammers faced civil suits brought by Internet service providers.

Experts warn that it is difficult to link alleged spammers to evidence extracted from the circuitous paths of cyberspace, but they say such laws can help if they are enforced.

Spammers "are folks who are fairly comfortable with playing . . . on the fringes of legitimacy and reality," said Ray Everett-Church, general counsel for the Coalition Against Unsolicited Commercial E-mail. "But if you can attach serious jail time, they would think twice."