Mail Assure supports both LDAP Authentication and LDAP Mailbox Sync, which use LDAP (Lightweight Directory Access Protocol) to query your company active directory to locate data about user's such as email addresses or login credentials.
LDAP Authentication allows Email users (end customer's) to access their Mail Assure Email Level Control Panel using their company credentials.
This is useful as it allows your users can access their mail in a business continuity scenario (if your directory is maintained on a separate server to your mailboxes).
See LDAP Authentication.
LDAP Mailbox Sync
LDAP Mailbox Sync keeps the Mailboxes list for the domain(s) in sync with the users listed in the company directory. This allows you to enable local recipient only delivery without having to maintain the list manually.
See LDAP Mailbox Sync.