I'm a somewhat newbie VPS administrator, having trouble setting up spamassassin SpamFilter (Frontend) version 2 (http://squirrelmail.org/plugin_view.php?id=146).  I'm running a VPS - Linux, Plesk 9.5.3, Apache 2.  Searched around everywhere possible before posting this.

I've copied it to server, configured/enabled it (with Option 8) and saved, and even restarted the web server.  Now I'm supposed to be able to see it in my webmail, under the Options section.  It should have a new link for "Spam filter configuration", where each user can set their spam identification settings, right?
But nothing has changed in webmail.  Is there anything special to know about activating Squirrelmail plugins on Apache?