Loosing spam fight

[Roland Smith]

On Sat, Jan 27, 2007 at 12:57:08PM -0200, JoaoBR wrote:
> On Saturday 27 January 2007 12:10, you wrote:
> > On Sat, Jan 27, 2007 at 10:58:46AM -0200, JoaoBR wrote:
> > > also a point to think about, most complains about spam talk about
> > > bandwidth consumption, by asking for resend later you certainly increase
> > > bandwidth consumption and resources on both sides
> >
> > Most spammers do not bother to return if they get a resend request.
> > That's the whole point of doing this. So practically it doesn't increase
> > bandwidth consumption.
> 
> you must see both sides, following your theory, spammers stay away but good 
> guys *are* coming back, greylisting is at the end the same only a little bit 
> less stupid than this anti-spam-send-and-ask-a-confirmation-mail things

Greylisting makes use to the features of the SMTP protocol that spammers
usually don't bother to implement, because it would make their programs
more complicated and would decrease their delivery rate considerably.

> also that spammers don't come back is an illusion, 

According to http://projects.puremagic.com/greylisting/whitepaper.html
it's not an illusion.

> firstable they do it for 
> money and secondable if they don't come back from the same source they come 
> back from another and either one might be spoofed so you can greylisting 
> yourself to death because sooner or later all sources are blacklisted or 
> you're rewriting continuously your whitelists and both are probably 
> unreliable at the end

Read the abovementioned whitepaper. And remember that there is no silver
bullit against spam. Greylisting, SPF, spamfilters etc. all have their
place and use.

Roland
-- 
R.F.Smith                                   http://www.xs4all.nl/~rsmith/
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