Info: Migrate security groups and delegates The Office 365 email migration service cannot detect whether on-premises Active ...

Info: Migrate security groups and delegates The Office 365 email migration service cannot detect whether on-premises Active Directory groups are security groups, so it cannot provision any migrated groups as security groups in Office 365.  If you want to have security groups in Office 365, you must first create an empty mail-enabled security group in Office 365 before starting the cutover migration.  You should also understand that Exchange cutover and staged migrations only move mailboxes, mail users, mail contacts, and mail-enabled groups. If any other Active Directory object, such as user that is not migrated to Office 365, is assigned as a manager or delegate to an object being migrated, they must be removed from the object prior to migration. Learn more at  Security Groups and Delegates.