To enable and disable Spam Assassin please do the following:
Just setup Spam Assassin once, and it works for all of the emails on your account.
Spam Assassin will mark your spam so it is easy to notice.
SPAM BOX
You can use Spam Box to move the spam from your Inbox to a SPAM folder on the server, so it won't be delivered to your computer.
Spam Box can be set up by clicking on the 'Enable Spam Box' option on the Spam Assassin screen.
Spam Box will deliver any emails identified as spam by SpamAssassin into a separate mail folder named "spam". This "spam" folder will fill up and should be emptied regularly. The Spam Box can only be checked by logging into webmail, and your desired webmail program must be setup to see the spam box (instructions below).
SquirrelMail Webmail:
Login to Webmail and choose SquirrelMail
Click on "Folders" at the top
Under the "Unsubscribe/Subscribe" area, select the SPAM folder and click "Subscribe"
Horde Webmail:
Login to Webmail and choose Horde
Click on "Mail" at the top
Click on "Options" at the top
Click the "Server and Folder Information" link in the first column
Under "Spam folder:" select "Create a new Spam folder".
Enter the name spam and click Ok.
RoundCube Webmail:
Login to Webmail and choose RoundCube
Click on "Personal Settings" at the top
At the top, click on the "Folders" tab.
Look to the bottom for "Create new folder" and in "Folder name:" type spam.
Click the Create button.