How can I check why Spam Assassin applied a particular score?

Symptoms

Some email messages are flagged or rejected as spam, but I'm not sure why. Can I check how Spam Assassin is applying this score?  

Description 

There may be times you need to find out more information for a specific mail message and find out why Spam Assassin applied a particular score to the mail message. You can use the below command to verify the scores.

Workaround

You can use the following command to read the rules applied:

su cpaneleximscanner -c '/usr/local/cpanel/3rdparty/perl/530/bin/spamassassin -D' -s /bin/bash < /path/to/message/in/mime/format.txt