Setting up BIND 9.2.3 as a caching name server on a mail server question

[Jason Williams]

Hello everybody. As the subject states, I would like to setup a caching 
nameserver on my mail server to speed up spam checks as well as alleviate 
usage of my ISP's DNS server.

Currently, I have a mail gateway server running FreeBSD 4.9, with 
SpamAssassin, Clamav and Sendmail. Everything has been working great and 
now im looking to add a caching nameserver.

I have made a package for the server and plan to install it here in the 
next couple of days, but I wanted to ask a couple of quick questions.

First, I would like to enable some logging of some sort, so I can see what 
all is going on with BIND, the querys etc.
Second, I have setup my firewall to port forward traffic to the mail server 
that BIND will be running on. Only port 25 traffic is allowed to the server 
from the outside world. But, I would still like to make my setup as secure 
as I can. Any suggestions or tips on other things I can do during the 
setup? Maybe something like only allow the localhost to contact named? Not 
sure if that is possible though.

For now, that is all I can think of. Late on Friday night and I need to go 
home. :)

I appreciate the help and look forward to your responses.

Cheers,
Jason