You can access detailed system requirements for Lotus Protector for Mail Security at the following link.
Lotus Protector for Mail Security includes a Linux operating system and runs as installed software in a VMware partition. It is designed to provide protection for organizations of all sizes, the Lotus Protector for Mail Security software appliance is available in two deployment options:
Software appliance: Install the Lotus Protector for Mail Security software appliance on off-the-shelf IBM System x® hardware and deploy as a physical appliance. The Lotus Protector for Mail Security 2.8.3 software appliance is certified to run natively on high quality, cost-effective Lenovo System x hardware as a physical appliance.
Virtual Appliance: Install Lotus Protector for Mail Security on supported VMware software and deploy as a virtualized appliance. Lotus Protector for Mail Security 2.8.3 is certified to run on VMware as a virtual appliance. Ideally suited for small to midsize businesses and scalable to more strategic operating specifications as required.