Combating the zombie army: PCs hijacked by spammers to act as proxy e-mail servers--so-called...

SPam is the bane of our email lives. It is irritating for users, causes downtime for businesses and presents an ongoing challenge for internet service providers (ISPs). Spammers aim to grab as much money as they possibly can through unsolicited, commercial email--whether for themselves or for third parties. Their relentless, psychological tricks outwit users far too often.

That's not to say they're unstoppable. The defences to combat spam are growing ever more powerful but new spamming techniques continue to emerge, demanding a variety of tactics to deal with them.