The following instructions will let you redirect flagged spam to an alternate address and not have it deleted automatically.
1) Make sure SpamAssassin is turned on. Any level of spam score will do, because you’re going to set up a custom filter outside of SpamAssassin to determine what you want to do with flagged spam. Make sure auto-delete is turned OFF.
2) Then go to User Level Filtering in cPanel and click “Manage Filters” by one of the addresses (if you want to redirect spam for a particular email account)
2) Then go to Account Level Filtering in cPanel (if you want to redirect spam for ALL email accounts on your hosting plan).
3) Click on “Create A New Filter”. In the first select menu (under Rules), choose one of the spam-related rules, based on how you want to identify flagged spam.
4) Examples of filters:
Example: “Spam Bar” is mail header created by Spam Assassin when it flags an email as spam. Mail flagged as Spam with a level of 3 would have a Spam Bar header of “+++”, so in the Rules you’d choose “Spam Bar” “contains” “+++” (this would catch spam with a value of 3 or higher).
Example: Another option is “Spam Score” (this is more precise), because mail can be flagged with a spam score of 2.1, 3.7, etc. So for Rules, choose “Spam Score” “is above” then enter “30” in the value field. This will cause all mail with a spam score of 3.1 or higher to be caught by this rule. If you want it to capture spam scored 2.5 or higher, enter “24” for the Spam Score, and so on.
5) Then in the Actions field, choose “Redirect to email” from the select menu and enter the email address where you want flagged spam sent to.