User Level Filtering allows you to set different filters for any single e-mail account and they are processed after the main account's filters.
To set the user level filters, log-in to your cPanel control panel and, in the "Email" section, click on "E-mail filters".
Then select "Manage filters" on the email account you're interested in and then click on "Create new filter". Choose a name for the new filter and add some rules about the objects, addresses and contents of the messages you want to block. In addition, you can regulate several actions such as, for example, sending messages to other e-mail addresses or discard them.
After setting all the rules and actions you wish, click on "Create" to end the operation.