Micro Focus Voltage SecureMail (formerly HP SecureMail) is an email encryption platform based on technology acquired with Voltage Security (February 2015) by HPE and then acquired by Micro Focus in 2017.
A compliance tool - if you are aiming for your organization to become PCI compliant or even POPIA/GDPR compliance this will aid you in your journey. Protection of data within your organization in the event of a data breach. Test Data Management, in the use case of your Developers having too much production data to test with, we can encrypt the data and then move to the necessary areas showing almost real life data sets to be used.
I think SecureMail is showing its age -- it is based on the Voltage product that HPE purchased a few years ago and hasn't really been updated since then substantially. Its documentation and web portal aren't as useful as some of the other products, and Zix has better DLP integration that is part of the base product, rather than an add-on