SEATTLE — With the arrest Wednesday of a Seattle man accused of sending out tens of millions of spam e-mails, federal prosecutors say that computer users across the globe should see a significant drop in spam messages.

Robert Soloway, a 27-year-old dubbed the "Spam King" by Interim U.S. Attorney Jeffrey Sullivan, was arraigned Wednesday on 35 counts of mail and wire fraud, aggravated identity theft, money laundering and fraud in connection with electronic mail.

Soloway is the first spammer whom federal prosecutors have charged with aggravated identity theft. The charge stems from his alleged theft of identities and business names for his widespread e-mail broadcasts — which included advertisements for diplomas and penis enlargement, said Assistant U.S. Attorney Kathryn Warma.

Soloway is accused of, among other things, defrauding customers who paid him to send out high volumes of commercial e-mail or who bought his software to send spam themselves. For $495, customers reportedly could have Soloway send e-mails to 20 million addresses for 15 days or sell them 80,000 e-mail addresses.

On his Web site, Soloway promised customers they would see a 400 percent increase in business within 90 days or he would give them their money back. He also claimed he had e-mail addresses for 157,800,000 people willing to receive spam.

But, Warma said, Soloway lied to his customers and "condemned them to a perpetual spam hell."

According to the indictment, the software sometimes did not work and Soloway's broadcast e-mails were sent with false headers to mask the sender's identity and used a proxy server to hide the originating computer.

Soloway faces up to 20 years in prison on the mail and wire fraud and money-laundering charges. The other charges carry lesser penalties. Warma said Soloway had been a spammer since he was a teenager.

The government also is seeking to have Soloway forfeit $773,000 that it says he earned from his enterprises.

In 2005, Microsoft won a judgment against Soloway for spamming. Soloway's company, Newport Internet Marketing, allegedly sent e-mails that appeared to have come from MSN and Hotmail addresses, both of which are owned by Microsoft.

Also that year, an Oklahoma businessman won a $10 million default judgment against Soloway in a claim he violated the federal CAN-SPAM Act of 2003 and Oklahoma's anti-spam laws.

Federal prosecutors say that Soloway, who lives in a high-rise apartment near Pike Place Market, claims he is broke and has not paid either judgment.

Soloway is reputed to be one of the world's ranking spammers. Brian McWilliams, author of "Spam Kings," puts him in the international dirty dozen.

"Clearly Mr. Soloway isn't the only spammer, but we want to send a message," Sullivan said.

Soloway is being held without bail pending a detention hearing on Monday.