> It might be worthwhile to add a black-hole route for cyberpromo's
> network into *.netbsd.org. 

You also have to have a black-hole route for cyberpromo into 
duality.gnu.ai.mit.edu, because that's the backup MX host for 
netbsd.org.  It's probably better to use sendmail rules (and or
modifications) to bounce the mail -- not that cyberpromo pays
any attention to mailer errors, but at least it bitbuckets their
mail effectively.

One single, solitary bogus SYN from every Spamford victim, and
the world would be a better place...