Check the header of an email

X-Spam-Status: No, score=0.1
X-Spam-Score: 1
X-Spam-Bar: /
X-Ham-Report: Spam detection software, running on the system "server.domain.com", has
identified this incoming email as possible spam. The original message
has been attached to this so you can view it (if it isn't spam) or label
similar future email. If you have any questions, see
root\@localhost for details.

You can also add Barracuda RBL to Exim in WHM

For cPanel /home/username/.spamassassin/user_prefs as described:

Other Resources:
http://www.toao.net/566-improving-spamassassin-accuracy-with-statistics