Spend a few more minutes on tweaking and improving your SpamAssassin configuration
Some more advanced SpamAssassin features that you may want to look at to tweaking and improving SA to your liking.
System-wide settings vs. user preferences
System-wide configuration is done in
but every user should have a
file in their home-directory where they can specify additional paramters or over-ride system wide settings. See the documentation on the SpamAssassin home page for more details.
Running SpamAssassin as a daemon and a client
Instead of invoking there relatively 'fat' spamassassin perl program for every individual email, you may want to run the daemonized version of spamassasssin: spamd. Instead of calling spamsassassin you would then only the very small client spamc. See the spamd readme for how this works.
You can have SpamAssassin learn to distinguish even better between spam and ham by telling it what you regard as spam or ham. After a few hundred emails SA will get even better at ranking the mails you receive. Look at the Bayes filter feature .
Before training SpamAssassin for the first time, review the contents of the your INBOX and Spam folders and make sure you have moved all spam emails from you INBOX to Spam (and all 'good' emails aka 'FalsePositives' from Spam to INBOX). Otherwise there is not much point in training SpamAssassin as it would recognize spam emails as ham.
Teach SpamAssassin to distinguish between Spam and Ham run
sa-learn --showdots --ham ~/Maildir/cur sa-learn --showdots --spam ~/Maildir/.Spam/cur
or schedule via cron.