Use global email filters to delete spam:
You can remove spam by using the Universal Email Filters program, which you can get from your cPanel control panel
Steps to set up email filters:
Step 1: Go to cPanel and log in
Step 2: Go to the e-mail section and select the global email filter
Step 3: Click on the Create New Filter icon below the Create Filter field
Step 4: Enter a name for the filtering process
Step 5: Add the new filter module