> -----Original Message-----
> From: John Palmer [mailto:nanog@adns.net]
> Challenge-response systems (such as TMDA) are the reason that
> our spam load has been cut down by 95%. I highly recommend systems
> like this.
I hate them, for several reasons:
- They generate collateral spam. If some spammer makes a spam run with an
address I own, I'm liable to get hundreds of challenges.
- They make *me* do extra work for the benefit of the receiver. Sorry, I'm
not willing to expend effort to sort *your* spam for you.
- They're often misconfigured with regards to list mail. I started to
really hate them about the time I posted to a popular mailing list and got a
dozen challenges in my inbox.
- They often contain a lot of advertising crap, which makes them a form of
spam themselves.
Generally I just trash all the challenges.