Pill pushers top spam offender chart

Health care-related email messages, primarily those marketing diet pills and Viagra, were the leading category of spam delivered to in-boxes in November.

A new study issued Tuesday by antispam software maker Clearswift showed that unsolicited email messages relating to health increased significantly last month. Perhaps more surprising is that pornography-oriented spam, once the primary scourge of people's email accounts, actually decreased over the same period.

Spam continues to be a major blemish on the face of internet commerce. The UK introduces its antispam law last week and earlier on Tuesday, President Bush signed the so-called Can-Spam bill, creating the first federal law regulating spam, a move backers say will be a major step in the war against email solicitations. However, some observers feel that email users aren't likely to see a decline in the volume of junk in their in-boxes as a result of the measure.

Clearswift's Spam Index, a monthly report that surveys the frequency and nature of unwanted email, found that health care-related messages accounted for nearly 50 per cent of all spam in November, compared with 27 per cent in October. However, porn-related pitches represented only 14 per cent of all spam last month, with finance-oriented messages accounting for 12.5 per cent of unsolicited emails.

Clearswift believes that the growth of health care spam shows that email marketers are taking the most interest in individuals who suffer from personal ailments and disabilities. The company said that email has proven the "ideal channel for selling products like Viagra" based on the confidential nature of the medium, which allows people to explore their options regarding the prescription impotence medication without consulting a physician.

Clearswift said health care email spammers also used the holiday season as a marketing tool for driving interest among consumers, using email subject lines such as "Lose Weight for the Holidays" to push diet pills. The company noted that nearly all health care spam was generated in the US, where online drug sales remain high compared with other regions.

"The growth of health care spam was directly related to the holidays," said Greg Hampton, vice president of US marketing at Clearswift. "We were actually surprised as it seemed more likely that direct product pitches would jump."

Direct product spam, which often markets products such as toys and electronics - typically popular holiday gift categories - represented only 10.5 per cent of unwanted emails last month.

Despite the decrease in porn-related spam for November, Hampton said it's unlikely that the category will disappear anytime soon. He said Clearswift has seen the rate of porn-oriented emails rise and fall from month to month as computer users and antispam software makers adjust their filters to catch new tricks aimed at sneaking the messages through, and marketers think up new ways to work around security applications. Legal issues among businesses and widespread distribution of parental control software has increasingly made pornography the most actively blocked form of spam, he said.

Clearswift's study surveyed 15,000 customers who received spam messages that circumvented the company's software. The company then randomly selected 1,000 of those emails and categorised spam messages based on their contents.

Matt Hines writes for CNET News.com