DNS Blacklist Script?

[Chris Maness]

Matthew Seaman wrote:
> You need to be very careful implementing something like this.  Most
> Spam nowadays is bot-generated and uses forged 'From' addresses culled
> from the address books on infected machines.  Unless you're careful,
> you're going to end up blocking a lot of completely innocent people,
> or worse, blocking your own legitimate e-mail users.
>
>   
DNS based blacklists are based on the senders IP address, not the forged 
from address.