How to hide users from GAL if they are AD Connect synchronized
How to hide and un-hide users from Global Address List (GAL) in Exchange Online if they are AD Connect synchronized Hiding User from GAL isn't possible if those are synchronized form On-Premises Active Directory. The local AD is the leading system for all important attributes, like SMTP, UPN and hiding from GAL. Especially during a cross-tenant migration, you do not want to see not migrated user in the GAL. Those User aren't actively working until their cut-over day. Since the Exchange Online attribute msExchHideFromAddressList s is an AD on-premises parameter, we have two possible ways hiding user in BME from GAL. Modify the AD Connect for your teant with a custom rule, by using a extensionAttribute to set the HidefromGAL. In this rule, for users which have an entry in the extensionAttribute, hiding / un-hiding will be controlled by AD Connect This is the best option for Cross-Tenant Migration, if you run 2 or more AD Connect system We direct modif...