Re: static versus dynamic nature of DNS: rate limiting

On Sun, Feb 22, 2004 at 02:33:56PM -0500, Yakov Shafranovich wrote:
> 
> Before getting into implementation details, we still need to figure out
> why sender verification will make any difference in the world where
> MyDoom computers are spewing spam.


It definitely will make a difference. The question is whether this 
difference will stop or just change spam.

My point of view is (since beginning of ASRG) that sender verification
is only the first half of fighting spam. That's useless as long as
everybody is able to anonymously lease a domain by sending a fedex
envelope with cash and a CDROM to the ISP. 

Once we have sender verification reliably working, we need to go into
the second step.

My guess is

- Whitelisting domains (enabled by smtp verification)
- Blacklisting of spammer-friendly countries and domain registrars
- Evaluating Whois-Entries


If a country is hosting too many spammers and doesn't outlaw spamming,
than the whole country will be blacklisted by most MTAs. That's the 
hard way, but I don't see any better at the moment.

My goal is to be able to accept mail only if I can determine whom I 
can effectively hold reliable in case of spam, worms,...

regards
Hadmut