Has anyone ever setup AAD Connect to sync with an existing Office 365 tenant and share their learning. We have an existing Office 365 tenant where all users have been created as cloud only, has Office 365 E3 licenses assigned and Exchange Online used for email. End users have different UPN in on-premises AD and AAD.
We are particularly concerned about Exchange Hybrid requirement that an exchange on-premises server is required in order to change mail related properties of synced objects. Given company migrated their exchange on-premises to Exchange online few years ago and there are no exchange on-premises servers any more. Would setting the sync now also require to re-configure Exchange hybrid again.