The worldwide market for anti-spam technology will be worth around £950m in 2008, up from £167m in 2003.
The forecast is from analyst IDC, which said that the growth is in response to spam changing from simply being a nuisance for business to a serious security threat.
A number of spam messages now contain viruses, worms and spyware or are used for phishing attempts by international criminals.
IDC has predicted that the worldwide revenue for anti-spam solutions will see a year-on-year growth rate of 42% through to 2008.
Brian Burke, research manager for IDC's security products service, said, "Whether the next several years will show continued improvements in the effectiveness of anti-spam solutions in reducing the costs of spam will depend on how quickly and well anti-spam solutions keep up with the latest spam innovations."
Analyst firm Gartner has predicted that Microsoft will offer a combined anti-virus and anti-spyware removal product for Windows desktops in the second half of this year.