1) Login to your cPanel and choose 'Spam Filters'
2) Under "Additional Configurations (For Advanced Users)" section, click on "Show Additional Configurations".
3) For Whitelisting, click on "Edit Spam Whitelist Settings" and "Add a new "whitelist_from" Item".
4) Enter all email address you wish to blacklist before pressing the "Update Whitelist (whitelist_from)" button.
5) The system will show "Success:The Apache SpamAssassin user preferences have been updated."
