Here is a step to blacklist an email using cPanel.
1. Login to cPanel and direct to the spam filter menu. Click the Spam Filters.
2. After click Spam Filter , you will redirect to Spam Filter setting. Check the ‘Automatically Delete New Spam (Auto-Delete)’ box:
3. Then, click the ‘Show Additional Configurations’
4. After that, click ‘Edit Spam Blacklist Settings’
5. Continue click ‘Add A New blacklist_form item’.
6. Here, you can enter an email that you want to block.
7. Click ‘Update Blacklist’ . Then, you are done.
