You know something has reached a critical point when it is written about in the Economist. This is now true about spam (as if we needed confirmation beyond looking at our mailboxes). Writes the Economist:
Why has spam taken off? The answer seems to be a matter of simple economics. Sending an e-mail incurs no direct cost. Even the cost of sending bulk e-mails is so small that a response rate as low as one in 100,000 justifies many bulk mailings (senders of physical junk mail usually need a response rate of one in 100). E-mail addresses on CDs sell for about $5 per million, and spamming software can be downloaded free from the internet or purchased for just a few hundred dollars.
The most reliable, though extreme, filtering approach is that offered by Microsoft’s Hotmail and other web-based e-mail services, which can be set to accept only e-mails from a specific white list of approved senders. But for most people this destroys one of the joys of e-mailreceiving unanticipated messagesand takes more time than they want to devote to managing their e-mail. One start-up, IronPort, is offering a system which employs a white-list of firms who post a financial bond guaranteeing good behaviour.
One new idea is challenge and response filters which bounce messages back to the sender, asking for a confirmation before accepting the message. Some spammers have already countered this ploy with auto-response software. Another new idea is software that statistically analyses the content of incoming e-mails to find spam, but this has yet to be widely tested and may also be vulnerable to counter-measures by spammers.