This article will walk you through adding IP addresses to a whitelist in WHM so they are not checked against RBL lists such as Spamhaus.
We first need to log into WHM and select the Basic Editor tab in the Exim Configuration Manager interface to modify your server’s Exim configuration settings.
Next, scroll down until you see the following option:"Whitelist: IP addresses that should not be checked against RBLs"
Add each IP address you would like to whitelist, separating each IP with a new line, example:
We have some more detailed information about the Exim Configuration Manager in our documentation here.