By default, WHM gives you the option of using Spamhaus and/or Spamcop for added SPAM protection for incoming email. If you have additional DNSBL’s (DNS-based RBL’s) that you want Exim to check email against, you can easily enable them if you’re running cPanel 11.28 or higher.
First, go to WHM > Exim Configuration Editor, and click the RBLs tab. Click Manage Custom RBLs, and you’ll see a list of any existing RBL’s that have already been enabled.
Under Add a new RBL, enter the information for the RBL you would like to add:
RBL Name: the name of the RBL, used only for reference
RBL Info URL: the url that shows up in bounce messages for blocked email, telling the sender where a lookup can be done to verify or remove a listed IP
DNS list: The hostname of the DNSBL