perl - Spamassasin: Check mailbox for spam

How can I have spamassasin check a mail folder for spam and move it into a different one.

I've been getting a lot of spam recently and started implementing bayesian classifiers. I moved a bunch into a separate folder and trained it with 'sa-learn'.

Now I want spamassasin to use what it just learned and check all email in a folder for spam and move it into the spam folder if it considers it spam. (e.g. the Spam-Level is higher than 5.0 in my configuration.)

EDIT: I am storing my emails with the maildir format on the server.

Any idea?

Thanks in Advance