You’ve got spam! Here’s a new reply

In the battle against spam, there’s a new sheriff in town.

It’s called “challenge-response,” an awkward name for an impressive regimen that can block almost every get-rich-quick, miracle-cure, buy-a-doctorate-degree, pornographic and other-kind-of-unwanted advertisement before it gets to your e-mail box. And it accomplishes this without using the type of filters that are the current anti-spam weapon of choice but often fallible.

Turning on challenge-response for the first time is like going from a chaotic room with everyone shouting at one another to a quiet cottage with only the occasional welcome visitor.

Several companies offer challenge-response programs, each with its own advantages and disadvantages. But they all work in basically the same manner.

They start by allowing only e-mails from senders on a user’s preapproved address list to reach the inbox.

Think of them as electronic bouncers, letting through those on the guest list and turning away all others.

That’s the challenge part, and if it were the only component to the program, e-mails from a long-lost buddy, someone who recently changed e-mail addresses or the friend-of-a-friend who is planning a party wouldn’t stand a chance.

That’s where response comes in.

A return e-mail goes out to all those that were blocked. It asks the sender to click on a link and the original e-mail -- as well as any sent in the future -- will go through. (At least until a user chooses to block future e-mails from that sender.)

A spammer, who sends out thousands if not millions of e-mails at a time -- often from fake addresses -- probably will never see, let alone answer, a verification request.

Allowances can be made for bulk or automated e-mails you want to get.

For example, maybe you signed up for an occasional electronic newsletter concerning a hobby. Or perhaps you bought an airline ticket online, resulting in an e-mailed confirmation and receipt. In either case, a verification reply would likely go unread.

But the more sophisticated of the challenge-response programs allow you to scan recently blocked e-mails to make sure you didn’t miss something. And once e-mail is approved from one of these sources, future e-mails from the same address should go right through.

The Spamarrest program (www.spamarrest.com) is particularly good at providing users a look at how much spam they are avoiding. While using it in a 24-hour period on a busy e-mail account, I received 86 e-mails.

Of these, 59 -- more than two-thirds -- were spam.

It was enormously satisfying to know that this junk e-mail was stuck out there in a cyber limbo. Several times while testing these programs I found myself looking over lists of the blocked messages and allowing myself a little victory laugh at their expense.

Shields up, Scotty, they can’t get to me now.

There are drawbacks, however.

Challenge-response programs are not appropriate for businesspeople who need to get a lot of e-mails from senders they don’t know. Would-be customers or clients might not be willing to go through the process.

And for someone who depends on receiving bulk e-mails from a variety of sources, going through blocked message lists to look for the good stuff might be more time-consuming than dealing with the spam itself.

The setup of a challenge-response program can be a bit daunting and often requires changing long-established settings.

In many cases, settings will have to be altered so that your e-mail first goes through the challenge-response company’s own server, where the approval and blocking takes place (this re-routing causes a few minutes’ delay of e-mail getting to you, but nothing major).

It isn’t too hard to find those settings and modify them, but don’t forget the first rule of making a major adjustment to your computer settings: Copy down your old settings so you can easily go back to them if need be. Also, it’s a good idea to do this when help lines are open.

Directions to set up Spamarrest are particularly clear, and they allowed for a fairly easy transformation of my address book, which resided in my hand-held computer program, into my approval list. The whole setup process took about two hours.

Spamarrest costs about $35 a year. Its big drawback is that it can’t be used by customers of the biggest Internet service provider, America Online.

Mailblocks (www.mailblocks.com), which costs $9.95 a year, can be used by AOL customers. The program is more complicated to set up, especially in regards to approval lists. In most cases, uploading an entire address book is not possible. It currently works only on Windows-based machines, but the company is developing a Mac version.

Qurb (www.qurb.com) has a one-time fee of $24.95, but it works only on Microsoft Outlook for PCs. (It won’t work with Outlook Express, the popular free version of Outlook.)

Internet service provider Earthlink (www.earthlink.net) has added a challenge-response component to its spam filter program available at no additional charge to subscribers. It’s also Windows-only, with a Mac version due by year’s end.

Could challenge-response be beaten by a relentless hacker? Maybe it already has.

During the testing, one totally unsolicited e-mail got through, offering discount price quotes on new cars.

According to the challenge-response program in use at the time, the sender activated the verification link. Whether this was done by an automated process or individual is unknown.

In any case, I plan to enjoy an almost completely spam-free life, at least for the time being.

Now if only I could do something about the telemarketers.