Contact Groups let you easily control which contacts on your account are alerted when a host is listed. You can specify as many Contact Group on your account as you like- every host could have their own Contact Group if you want.
Contact Groups can be added via the Manage -> Contact Groups section of the RBLTracker portal. Simply enter name (label) of the Contact Group, and click “Add New Contact Group“.
Once the Contact Group is added, it can be selected when adding / editing Contacts, from the Manage -> Contacts section:
And can be selected when adding / editing Hosts, from the Manage -> Hosts section: