The advent of the Christmas holiday season has brought with it a more than 20 per cent increase in the volume of spam traffic, according to a statement released by Brightmail.

The San Francisco-based company, which sells products and services that help companies identify and block email viruses and spam, processed over 16 billion spam messages in the past 30 days, a 21 per cent increase over the number of spam messages blocked in the 30 days prior to the Thanksgiving holiday, according to Brightmail.

The company, which was founded in 1998, said that it had noted the increase in spam traffic in the weeks leading up to Christmas and New Years in previous years, and that it was prepared for the increase in spam traffic this year.

Brightmail's statistics are accumulated from approximately 130 customer sites, which include six of the top 10 Internet service providers (ISPs) in the US, as well as leading ISPs in Europe and Asia, according to Enrique Salem, president and chief executive officer of Brightmail.

The company's software protects about 250 million email accounts, Salem said.

Decoy email Brightmail develops its knowledge of spam messages from its Probe Network, which is described on the company's Web site as a collection of decoy email accounts that are specially designed to attract spam messages. The network has a "statistical reach" of over 100 million mailboxes, according to Brightmail.

All messages that land in the decoy email accounts are considered by Brightmail to be spam. The company uses the network of accounts to detect developing spam attacks and to create filter rules that its customers can use to block the spam from their own messaging servers.

The uptick in spam is due primarily to increased product solicitations linked to the Christmas shopping season, Salem said. The soft economy may also play a role.

"What's the cost of sending an email? It's almost free. So (spam) is a way of getting your message out at a low cost. The economic side is favourable," Salem said.

The flood of spam traffic generally dies down after the New Years holiday, according to Brightmail. However, that respite may be short-lived.

"Last year, there was also a bump in the holiday season, but it didn't drop off. It was sustained and then kept growing. People harvested email addresses, then just kept using them throughout the year," Salem said.

Spammy new year Brightmail predicted a continued increase in the volume of spam during 2003. Spam already made up 40 per cent of all Internet email traffic in 2002, up from just 8 per cent of email traffic in 2001, the company said.

Statistics released by Brightmail show that of the more that 5.5 million unique spam messages detected by the company in November, more than 75 per cent were solicitations for consumer products, financial services, and adult content.

The remaining 25 per cent of spam messages were linked to online scams or offered information on health, spiritual, leisure and other topics, according to Brightmail.