This article confirms the official tool used by Symantec Email Security.cloud service in order to Detect and fix the misconfigurations that leads to data breaches and compliance violations.
Email Security.cloud
You would like to know which CSPM tool is deployed for the Email Security.cloud services.
Email Security services deploys Prisma By Palo Alto as the official Cloud Security Posture Management tool.
https://www.paloaltonetworks.com/prisma/cloud/cloud-security-posture-management