Updated

The government has been successful in shielding many Americans from unsolicited telemarketing phone calls, an Associated Press poll found, but is finding it more difficult to cut down on the growing flood of e-mail "spam."

The AP-Ipsos poll found that three-quarters of the people who signed up for the do-not-call list (search) reported fewer telemarketing calls. It also found that few people noticed any difference in the amount of junk e-mail they've received in the six weeks since a law intended to cut down on spam took effect.

More than 57 million phone numbers have been placed on the do-not-call list since it was established in October, according to the Federal Trade Commission (search). Because many of the numbers may be cell phones or multiple phones within the same household, the FTC does not claim to know what percentage of the population has registered.

The AP poll, conducted by Ipsos-Public Affairs, found half of those surveyed were on the list. Among that group, 74 percent said telemarketing calls have decreased, with many saying the drop is significant.

"I get hardly any of those calls anymore," said Mary Ellen Kutschke, 53, of Farmington Hills, Mich. "I like it. Invariably, those calls would come in when you were right in the middle of doing something like making dinner. It was all a total waste of time."

People can register numbers or file complaints at www.donotcall.gov or by calling 1-888-382-1222. Companies that call numbers on the list face fines of up to $11,000 for each violation.

Earlier this week, a federal appeals court in Denver upheld the registry, rejecting telemarketers' claims that it infringes on their free speech rights.

The government says people on the list can expect about 80 percent of telemarketing to be blocked. Exempted are charities, pollsters and political campaigns, as well as companies that have recently done business with someone on the list.

Those who have signed up for the list were more likely to be middle age or older, white and have college degrees, the poll found. Residents of the Northeast and Midwest were more likely to sign up than those in the South and West.

The poll found little progress in the fight to reduce unsolicited commercial e-mail, or spam. Of the e-mail users surveyed, 53 percent said they get a great deal of spam and 24 percent said they get some.

The flow of offers on dietary aids, sexual enhancements and financial help hasn't made many people limit their e-mail use, but it is an aggravation.

"It increases every day," said Kristie Krouse, a 28-year-old contractor from Pensacola, Fla. "I just delete it."

The anti-spam law (search) prohibits senders of unsolicited commercial e-mail from disguising their identity by using a false return address or misleading subject line. It also prohibits senders from harvesting addresses off Web sites and requires such e-mails to include a mechanism so recipients can indicate they do not want future mass e-mailing.

Almost seven in 10 in the poll said they have seen no difference in the amount of spam since the law went into effect. About one in 10 said it has increased.

The anti-spam bill encourages the Federal Trade Commission to create a do-not-spam list of e-mail addresses, something FTC officials have said could be difficult because of the decentralized and unregulated nature of the Internet.

Ken Holland, a 56-year-old engineer from Mobile, Ala., burst out laughing at the idea of a "do-not-spam" list, which he said would only invite more spammers. Holland uses several tricks to cut down on spam, such as changing e-mail addresses periodically and setting up temporary e-mail accounts when registering for services online.

More than nine in 10 in the poll said they have never bought anything from a spam offer.

"Heavens no," Holland said. "Even if there was something that caught my eye, I wouldn't order it from a spammer."

The AP-Ipsos poll of 1,000 adults was taken Feb. 16-18 and has a margin of sampling error of plus or minus 3 percentage points, larger for subgroups.