You've added a list of emails domains as requested, as part of configuring a new Cloud Detection Server (CDS), in the Cloud Management Portal (CMP).
Email domains were previously required in order to set the configuration of "accepted sender domains" for the Cloud Service for Email.
Release : 15.7+
When you login to CMP to configure a Cloud Detector - you need to provide several details,depending on what kind of CDS is being configured.
For Email Detectors, the list includes:
As it turns out, the "domains" are no longer an essential detail - because that list is actually obtained AFTER the provisioning of a new Cloud Service for Email Detector:
*The reason we used to require email domains was that prior to DLP 15.1 MP1, customers in Reflecting mode couldn't manage domains via the Enforce Server, so the DLP Cloud Operations team required you to submit all domains at the time of provisioning.