To Configure the Blacklist of Spam Filters, perform the following steps:
1 – Open cPanel (yourdomain/cPanel).
2 – Click on (Spam Filters) from Email section.
3 – Click on Show Additional Configurations.
4 – Click on Edit Spam Blacklist Settings.
5 – Click on Add A New “Blacklist _from” Item.
6 – Enter the domain name or email in Blacklist_from box.
7 – Click Update Blacklist (Blacklist_from).