The volume of junk e-mail has reached a critical threshold that requires swift action to protect the Internet correspondence millions of people take for granted, regulators said Friday at the end of a three-day forum on "spam."

"Things are worse than we imagined," said Eileen Harrington, the Federal Trade Commission's director of marketing practices. "There is consensus that the problem has reached a tipping point. If there are not immediate improvements implemented across the board by technologists, service providers and perhaps lawmakers, e-mail is at risk of being run into the ground."

Harrington said that was the impression left by the dozens of technology experts, government officials, industry executives and lawyers who flocked to Washington to discuss the problem of unwanted commercial e-mail and what to do about it.

In March, 45 percent of all e-mail sent was spam, according to Brightmail, the San Francisco-based anti-spam company. That's up from 16 percent in January 2002.

Most of the panelists at the FTC forum on Friday agreed that a strong federal anti-spam law is needed and would be better than the mix of local laws now in 29 states.

Steve Richter, an attorney with the E-mail Marketing Association, said the current patchwork of laws is confusing and harmful. He gave the example of a Washington state resident who receives spam from New York relayed through a computer in Nevada.

"What law can you tell either of the parties -- the sender or the recipient -- to follow?" he said.

Virginia enacted the nation's harshest anti-spam law Tuesday, giving authorities the power to seize assets earned from sending bulk unsolicited e-mail pitches while imposing up to five years in prison.

Rep. Zoe Lofgren, D-Calif., said this week she would seek federal legislation offering rewards for individuals who help track down spammers. Sen. Charles Schumer, D-N.Y., proposed a national "do-not-spam" registry similar to an FTC service that is to begin blocking unwanted telemarketing calls this fall.

A pending anti-spam bill proposed by Sens. Conrad Burns, R-Mont., and Ron Wyden, D-Ore., would require spam to have valid return addresses.

Some were skeptical that the federal proposals would do the job.

"New laws that are unenforceable for myriad reasons or that are overtaken by the advances of technology have the potential to do more harm than good," FTC commissioner Orson Swindle said. "No single law, no single new technology, no new initiative, no new meetings are going to solve this problem alone."

John Patrick, chairman of the industry-supported Global Internet Project, said any U.S. law would do little to stop spam from other countries and the only solution is blocking it with new technology.

Earlier this week, AOL, Yahoo! and Microsoft announced a joint initiative to combat spam through techniques such as identifying and restricting messages with deceptive headers.

Persistent spammers have found ways to dodge similar obstacles.

Harrington said the automated tools spammers use to "harvest" e-mail addresses are "far more efficient and effective than we knew."

"Spammers are provided with an endless menu of new and fresh e-mail addresses to send to," she said. "That accounts for a good deal of the exponential increase in volume."

In 2001, the FTC received 10,000 junk e-mails each day forwarded by complaining consumers. The agency now receives 130,000 messages daily.

Other topics during the forum included the potential for spam to migrate to the screens of cell phones and the effect of spam in other countries.

Motohiro Tsuchiya, a communications professor with the International University of Japan, said Friday that about 80 percent of spam in Japan comes from outside the country and most of it is in English.

"We are now importing more spam from the United States," he joked. "We are actually learning what American culture is through spam."