Many clients are facing the issues with the Unwanted emails which are received from unknown clients in the Inbox. So there is a Function(Apache SpamAssassin) in the cPanel which will Allow and Block the Email from the unknown clients. It means you can easily Blacklist(Block) and Whitelist(Allow) the Email address by yourself.
Blacklist(Block) an Email Address
1) Login to your cPanel.
2) Open “Apache SpamAssassin™” under the Mail Section.
(Note. If the Apache SpamAssassin is disabled then you need to enable it by click on the “Enable” link.)
3) Once Apache SpamAssassin™ is enabled then go to bottom of the page and click on the “Configure Apache SpamAssassin™” button under Apache SpamAssassin™ Configuration.
4) Now you will see the Name “blacklist_from” and enter the Email Address which you want to Block(Blacklist).
5) Now Click on the Save Button to save this Successfully.
Whitelist(Allow) an Email Address
1) Login to your cPanel.
2) Open “Apache SpamAssassin™” under the Mail Section.
3) Once it will open then go to bottom of the page and click on the “Configure Apache SpamAssassin™” button.
4) Now you will see the Name “whitelist_from” and enter the Email Address which you want to Allow(whitelist).
5) Click on the Save Button.
Now the Email address successfully whitelisted.