For IT organizations it is an ongoing battle. Australian accounting firm BDO Kendalls' IS director Michael Axelsen says the problem "is getting worse" instead of better.

Axelsen said spammers are more insidious in their phishing expeditions and it means internal resources are being directed to a non-productive activity. He estimates 30 to 40 percent of e-mail is spam, which is wasting a lot of bandwidth.

And while the organization uses antispam software and subscribes to black lists, Axelsen said end users still waste a lot of time deleting unwanted mail.

"It would be great if it could go away the way vendors are claiming it can be done; I'm not sure if charging Internet service providers (ISPs) is a practical solution," he said.

Australia is introducing a new code of practice for companies providing or enabling e-mail services from July 16, 2006, to support the Spam Act of 2003.