[Dovecot] Any way to let dovecot block pop3 attempts?

[Steve Campbell]

Is there a way using dovecot facilities to block an IP from attempting 
POP3 connections (similar to the sendmail access file for smtp 
connections)? I usually do this at my border firewall, but if there's a 
quick and dirty way in dovecot to do this, it'd make life a little simpler.

Thanks
steve campbell