Noob questions

Hello all--Vernon has been patiently answering all my tech-newbie 
questions, so I thought I'd give him a break and inflict them on the rest 
of you for a while.

Just a couple for now.  I can see the X-DCC headers, and it's scoring 
things as it should.  At some point in the future I plan to move this into 
Sendmail's bailiwick, and have it reject spam based on the DCC score.  
First I am, as advised, just watching it for a while to see what kind of 
score the mail is getting.

So: How do I recognize when something would have triggered the "spam"
threshold, and been rejected?  Will it be painfully obvious--when I do get
spam, will I be seeing the X-DCC header and thinking "Oh yeah, message-ID
score over 2000, that would have bounced"?

And second, is there any particular reason to have both a server whitelist 
and a client whitelist?

Thanks to all in advance!

-Bertha
-- 
If I save time, when do I get it back?