I just setup a new server with vanilla SA on CentOS 5 and a lot of obvious
drug/stock/foreign stuff is getting through. I have verified that DNSBL
is being used. In general, I would like to know what the prevailing
wisdom is as to increasing the agressiveness of my filter.

Are there certain plugins that I need to make sure are working? If so
what are they?

Will SA get better as it considers the input?

Also, if I drag spam from the inbox into the Spam folder, will SA learn
from that? If I drag non-spam out of the Spam folder will SA learn
from that?

Is there a way to add the X-Spam-Report to regular messages for a while
so that I can see exactly why it's getting through?

How do I properly activate filtering based on character encodings used
in messages? Basically I want to severely penalize non-Latin1 encodings.