Re: [PLUG] OT: spammer's DNS

[sean finney <seanius@seanius.net>]

hiya,

On Wed, Apr 01, 2009 at 08:40:16AM -0400, Art Alexion wrote:
> Real mail stopped going to the old server in about 48 hours, but spam still 
> goes there.  Can anyone help explain how the DNS servers that spammers use 
> differ, and why this happens?

spam servers (and infected zombies) are usually the least standards-complaint
systems out there, so i wouldn't think about it too hard.  maybe they have a
poor implementation of DNS caching, or maybe it's intentionally designed that
way.  

thankfully, such non-compliance is also what gave birth to greylisting
and other effective anti-spam techniques :)


	sean

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