Comments on: Why I hate Challenge-Response

By: M. van Bezouw

M. van Bezouw — Sat, 22 Nov 2008 18:48:05 +0000

That was a bad CRS (Challenge response system) implementation you ran into.
But don’t let you be discouraged by this because there are better implementations.
Like XToME http://www.xtome.com

By: Frank Paolino

Frank Paolino — Wed, 12 Nov 2008 14:23:42 +0000

I hate C/R because it put the burden of your spam blocking on the senders of good mail! How’s that for shifting the problem to someone else!

By: Learning an email marketing lesson…the hard way | Commtouch Café

Learning an email marketing lesson…the hard way | Commtouch Café — Fri, 09 May 2008 05:00:17 +0000

[...] with partners and potential partners, we use the well-known CRM system, Salesforce.com. As I have mentioned in a previous post, we try to be very careful only to email people to who have requested to receive our mail. This is [...]

By: Seth Godin on Spam Filtering | Commtouch Café

Seth Godin on Spam Filtering | Commtouch Café — Wed, 23 Apr 2008 14:57:37 +0000

[...] worse than false negatives. If an anti-spam solution is promising 100% detection (unless it’s challenge-response, and yeah, it’s easy to provide 100% when you just block pretty much everything), I would [...]

By: Peter Louies

Peter Louies — Tue, 22 Apr 2008 22:18:01 +0000

Not only Challenge/Response is annoying for the sender and leads to undelivered emails, like newsletters and so on, but it also leads to spam backscatter.

Spammers send their message with spoofed email addresses. So the recipient receives the spam, sends a C/R back to the sender. But the spammer is spoofing the senders address and is using/abusing your email address. Believe me, this happens. Everyday I have clients who ask me how they can stop their domain being used in spam.

So, you get such messages in your inbox. Quite annoying.

We now got rid of the “virus intercepted” messages but mail server administrators will need to think twice when implementing C/R solutions.

By: Roger Carter

Roger Carter — Tue, 22 Apr 2008 18:42:34 +0000

This Challenge-Response paradigm reminds me what it’s like to discipline my teenagers. It’s just as frustrating and the only thing I know to do is wait for the “challenger” to grow up and join the real world.

Nice article!