'dialup-ranges?' Re: greylisting DNSBL hosts?

[cls@truffula.sj.ca.us]

[This message has also been posted.]
In article <2N0u0-7Xz-1@gated-at.bofh.it>, Kilian Krause wrote:
> 
> --=-+rYNsJkiW3Vja8Xh+ktl
> Content-Type: text/plain
> Content-Transfer-Encoding: quoted-printable

Please don't do that.  Quoted-printable is broken.

> 
> Hi,
> 
> I just came across a quite interesting idea.=20
> Greylisting naturally makes only sense if the remote end is no MTA, but
> a direct TCP connection. All MTAs will come back and thus greylisting
> will only introduce latency which most admins will see as neccessary
> tradeoff for reduced spam. Yet, why not use the knowledge of DNSBL to
> tell you which are the dialup-ranges of ISPs?

I'd like to know which DNSBL knows where "the dialup-ranges of ISPs"
are.  It seems to me the biggest and worst ISPs withhold that
information as some kind of trade secret.  I've been collecting the
ranges at SBC and the rest, one at a time, for years, as we receive
spam from them.  Never found any DNSBL that tagged more than
about 20% of them.  Admins at Verizon and Charter have each told me
they don't even have a reliable list of their own dynamically
assigned IP ranges for internal use.


Cameron