[SLL] collaborate on a dnsbl?

[Russell Evans]

On Fri, 13 May 2005 01:08:20 -0400
"Russell Evans" <russell-evans at qwest.net> wrote:

 
> If there are 14 million domains, say with an average of 4 mail servers
> per domain specified via spf, then we have 56 million target hosts.
> 
> It looks like ordb has 255,000 hosts in its rbl, depressingly it looks
> very steady. 
>  http://ordb.org/statistics/relaycount/
> 
> Interesting, by SMTP server
>  http://ordb.org/statistics/daemons/
>  
> 350 million hosts on the internet
>  http://www.isc.org/index.pl?/ops/ds/
> 
> 14 million domains
>  http://www.nw.com/zone/WWW/dist-bynum.html
> 
> 255,000 rbl hosts / 350 million hosts x 56 million targets = 40800
> statically infected mail servers in a spf world
> 
> 350 million hosts / 14 million domains = 25 host per domain
> ( at 25 hosts per domain, I think my assumption of 4 mail servers per
> domain is high. It probably only averages 2 per domain - 20400
> statically infected mail servers)
> 
> Because spf is domain based, spam could be blocked by domain rbls 
>  40800 infected servers / 25 hosts per domain = 1632 domains needing
>  to be blocked.


I goofed: my assumption was 4 mail servers per domain and I should have
used that number to determine how many domains would need blocking. 

40800 infected servers / 4 servers per domain =  10200 domains needing
to be blocked.

Thank you
Russell