We have a cloud server running Centos 5.8 x64 and WHM 11.34.0 and need some configuration assistance. We would like to have mail for some of our domains to be filtered through McAfee SAAS Email Protection (MXLogic). That is currently working (we simply changed the MX records on the domains to McAfee but set it as a local mail exchanger too), but that leaves a backdoor for spammers to get SPAM through by using the server IP instead of the MX record. We would like to close this backdoor but are unsure of how to. We can’t just limit all mail traffic at the firewall and allow only the McAfee IP ranges because not all mail domains on that server are flowing through the McAfee service. Have any ideas? 
Summary: How can we limit inbound emails for specific domains to a given range of IP addresses only? We can not limit it at the server or firewall level as not all domains on the server are using MXLogic.
Summary: How can we limit inbound emails for specific domains to a given range of IP addresses only? We can not limit it at the server or firewall level as not all domains on the server are using MXLogic.