Author: Martin A. Brooks Date: To: Marc Perkel CC: exim-users Subject: Re: [exim] An interesting observation about spam zombies
Marc Perkel wrote: > My theort is that spam zombies do DNS caching so as to maximize spam
> output by eliminating dns lookups. Thus zombies retain old information
> far longer than they are supposed to.
> So I'm experimenting with a blaclisting trick where I change my fake
> high MX records, wait several hours, and then anything that hits the old
> fake MX records are spam zombies.
Your theory is flawed. Many many large ISPs ignore TTLs and
overagressively cache DNS records.
Martin A. Brooks | http://www.antibodymx.net/ | Anti-spam & anti-virus
Consultant | martin@??? | filtering. Inoculate
antibodymx.net | m: +447896578023 | your mail system.
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