Susan C. Daffron

Award-winning fiction & nonfiction author

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January 5, 2007 By Susan Daffron

Understanding Challenge-Response Systems

The world of email gets more depressing every day. Recently, a reader told me she has only about a 50% success rate sending and receiving emails. The emails people send to her sometimes bounce back to the sender, and when emailing others, she often has to send second emails to make sure people got her first email. What a waste of time.

It’s easy to blame the Internet Service Provider (ISP) for these problems, and threaten to switch. However, the sad reality is that virtually every ISP is dealing with a deluge of spam. You may go through the agony of switching email addresses, telling all your contacts, and then be no better off with a new ISP when it comes to deliverability.

Every ISP has users screaming about all the spam they get, so to try and stem the tide, many ISPs have turned to email filters. But when they filter email to get rid of the bad stuff, good email is lost in the process. No type of filtering works completely and reliably.

To make sure I receive all my incoming email, my approach for many years has been to use the email address associated with my Web site domain, rather than an email address associated with an ISP. I can switch Internet providers without changing my email address. Plus because I log on to my domain’s mail server and get the mail directly, it isn’t filtered by the ISP.

Of course, that means I get to deal with all the spam myself. For many years, I have used programs like SpamCombat (http://www.glocksoft.com) to delete offensive mail off the mail server, so it is never downloaded to my computer. However, when I started getting many hundreds of spam messages a day, something had to give. Now I also use what’s called a “challenge-response” system. The one I use is called SpamArrest (http://www.spamarrrest.com). If someone sends an email to me and the email address is not in my approved list of senders, SpamArrest automatically sends an email (the “challenge”) with a link the sender must click (the “response”). Only emails from people who have responded to the challenge can get through. Real humans only have to click once for their email to get through to me from then on. Because spam messages are almost always fake, the senders never respond to the challenge and their slimy email is never passed through to me.

Of course, like anything else, challenge-response systems aren’t perfect. If you sign up for an email newsletter or receive other types of automated emails like a ship confirmation, you have to go into SpamArrest and approve it. Plus some people have so much filtering on their end that they never get the challenge email. Again, it’s simple to go in and approve those emails. We have many contact forms on all our Web sites (which all are preapproved), so no one has ever had trouble reaching us, one way or another.

The good news is that, according to the statistics, in the last 30 days, SpamArrest has prevented almost 8,000 disgusting messages from getting to my computer. Not seeing those emails is so worth the inconvenience of occasionally approving a newsletter.

Filed Under: Internet, Logical Tips Tagged With: E-mail

About Susan Daffron

Susan Daffron is the author of the Alpine Grove Romantic Comedies, the Jennings & O'Shea mysteries, and multiple award-winning nonfiction books, including several about pets and animal rescue. Check out all her books on her Amazon Author page.

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