Hello,
I am having trouble figuring this out. If possible, how can I add my own words
and/or phrases. Then have spamassassin flag messages with these words/phrases
as spam?
Pretty much the only way is to start writing custom rules... there is no simple "blacklist words" feature of spamassassin (having such a thing is contrary to the reasons SpamAssassin was invented in the first place).
I've got a guide which teaches you how to write simple to moderate complexity rules. It doesn't cover the super-fancy regex possibilities, but that's probably best left to a good guide on regex's anyway.
http://mywebpages.comcast.net/mkettler/sa/SA-rules-howto.txt
