Would it be possible to add rules based on the results of RBL queries?
For example, impose a very restrictive rate limit (or tarpit with spamd?) any
connection that got a specified RBL positive result.  Not necessarily limited to
SMTP, and could also work with other services as well (http spider bots).

I was googling around and the pieces just floated together, it seems to be a
good idea.

RBL Check for REMOTE_IP
http://answers.google.com/answers/threadview?id=369452

pf and spamd
http://www.benzedrine.cx/relaydb.html

Greg Padberg

Computer / Network Technician
Eston-Elrose School Division #33