LDAP server signing requirements – MS KB #4520412
As part of the March 10, 2020 update, Microsoft has added the ability to increase LDAP security by requiring LDAP Server Signing and LDAP Channel binding. These options are to prevent “… a man-in-the-middle attacker from successfully forward an authentication request to a Microsoft domain server which has not been configured to require channel binding, signing, or sealing on incoming connections.” These settings are explained in detail at https://support.microsoft.com/en-us/help/4520412/2020-ldap-channel-binding-and-ldap-signing-requirements-for-windows
We have tested these hardening policies, and determined that their implementation does not negatively affect communication between the SES server and Active Directory