Re: blocking dialups

[Ragnar Lonn <]

On Thu, 15 Oct 1998, Piet Beertema wrote:

>     If an ISP has a million customers and produces 100 spams per day it
>     is still a much better ISP, spam-wise, than one with 100,000 customers 
>     that produces 50 spams per day.
> Fine. How do I know if a given ISP falls in either category?
> 

Yeah it's hard. There would have to be someone gathering and analysing
statistics to determine that. You need to know that a certain IP 
belongs to a certain ISP/organization and that might not always be so
easy to find out. You'd probably have to use both WHOIS, DNS, and
routing information. Routing information is interesting as you'll be able
to determine the ratio between mail messages handled and spam messages
originated for a whole AS, judging how active that AS is when it comes to
enforcing anti-spam rules for itself and its customers.

There would have to be several participating sites sending in data about
how many mails they've received from various IP addresses, a bit like the
Freenix top1000 list for news transit servers work (although in that case
it is Path: headers that are submitted).

  /Ragnar