[Dovecot] Applying a DNS RBL to deny authentication?

[Marc Perkel]

Hope to get some attention about this idea to reduce hacking passwords.

Here is a list of about 700,000 IP addresses that are hacking passwords 
through SMTP AUTH

http://ipadmin.junkemailfilter.com/auth-hack.txt

This is a list of IP addresses that attempted to authenticate against my 
fake AUTH advertizing on servers with no authentication. We do front end 
spam filtering for thousands of domains and I decided to advertize 
authentication where there is none and I accept and blackhole all 
authenticated email to those servers. I have harvested the IP addresses 
in this list that is available through an RBL.


It seems to me that a nice dovecot feature would be the ability to do a 
black list check against IP addresses connecting and deny access if listed.

Thoughts?