The documentation set for Trend Micro Email Security includes the following:

Product Documentation

Document
Description
Directory Synchronization Tool User's Guide
The Directory Synchronization Tool User's Guide is a PDF document that introduces the Trend Micro Email Security Directory Synchronization Tool and explains how to use the Directory Synchronization Tool to synchronize groups, valid recipients and email aliases from Microsoft Active Directory, Open LDAP, IBM Domino and Microsoft Entra ID to the Trend Micro Email Security server.