Spamfiltering as user

[Elian]

Hi all,
I´m a user at a cPanel based server. Unfortunately I get a lot of mails through spam filter (Spam Assassin is enabled and set to 4.0 scores, Spambox is enabled, I get mails through Imap) - so i want to change some configuration to get it working better.
How can I figure out which tests are done by default at complete server - how can I add more tests?
Do I have any possibility as user to learn the bayesian filter? How can I do that? I´m using Horde as webmail...
Otherways I would like to use a already complete blacklist which is updated sometimes - like passwall. In my case its the german iX-Blacklist that I want to automatically update it every day then use it. How can I do that - might be using a cronjob, but I don´t know much about webserving and linux, so please help me... How do I have to configure SA to use that blacklist-file?

Thanks a lot,
Elian