I should add I also found the following scoring tweaks to be helpful in my system due to some specific spam that seemed to target us:
Code:
# Increase future date score to control Asian spam
score DATE_IN_FUTURE_12_24 3.599 3.599 3.599 3.599
score DATE_IN_FUTURE_24_48 3.599 3.599 3.599 3.599
# Increase scoring of miscellaneous ad-related traits
score RDNS_NONE 1
score HTML_MESSAGE 1
score HTML_OBFUSCATE_05_10 1
score HTML_OBFUSCATE_10_20 1
score HTML_OBFUSCATE_20_30 1.5
score HTML_OBFUSCATE_30_40 2
score HTML_OBFUSCATE_50_60 2
score HTML_OBFUSCATE_70_80 2.5
score HTML_OBFUSCATE_90_100 3
score UPPERCASE_50_75 1
score UPPERCASE_75_100 1.5
The bottom line is, once you have some basic settings in your system, you need to take a look at the headers of messages that are still coming through. See what is going on in those headers, that isn't properly being scored by your system. If you like, post a couple headers here and we'll look at them with you. Often it only takes a couple tweaks to the scoring to solve fairly significant spam problems...and once solved, I find it to be pretty much set-and-forget.