Whitelisting and Blacklisting domains or specific email addresses within the cPanel Spam Filter is easy and only takes a few minutes to complete. First you'll need to log into cPanel and search for Spam Filters, or find the Spam Filters Tab under the Email section.
Once inside the Spam Filters tab, scroll all the way to the bottom and select "Show Additional Configurations" under the "Additional Configurations (For Advanced Users)" tab.
Once you have selected "Show Advanced Configurations", you should see 3 additional options: Whitelist, Blacklist, and Calculated Spam Score. To add a domain or user to your Email Whitelist, select "Edit Spam Whitelist Settings". The next screen will have an option labeled "Add a New "whitelist_from" item", click on that and you will now see a text bar. Inside that text bar you can whitelist a few different ways:
domain.com: adding an entry this way will allow all traffic from the domain you entered.
*@domain.com: This will have the same effect as the entry above.
firstname.lastname@example.org: This will allow you to whitelist a specific email address while still filtering the remaining email traffic for that domain.
Once you have your entry complete, simply click on "Update Whitelist(Whitelist_From)" and your entries will be updated.
Blacklisting will function the same way as whitelisting under the "Edit Spam Blacklist Settings" tab.