If you're overwhelmed by spam like the rest of us, there aren't any really terrific solutions. You can try smarter spam filters, though you'll still have to verify that legit mail isn't swept up among the dross. You can switch . . .
If you're overwhelmed by spam like the rest of us, there aren't any really terrific solutions. You can try smarter spam filters, though you'll still have to verify that legit mail isn't swept up among the dross. You can switch to a new e-mail address and pray that nobody except friends and family ever learn it. Or wait a few years for micropayments, small cash payments required to deliver an e-mail that could make it uneconomical for spammers to annoy us.

But the spam-blocking technique that's attracted the most attention among start-ups recently is a very simple one: Challenge-response (CR) technology. When your mailbox is protected by a CR system, anyone who tries to contact you will be greeted with a response saying something like "click on this link to deliver this message" or "type in the word you see in the box above." Well-designed CR utilities won't challenge mail from known correspondents or mail that you specifically asked to receive.