Cloud‑managed Remote Mailboxes: Manage Exchange attributes in Exchange Online (and finally retire the last Exchange server 🚀)
TL;DR: Microsoft shipped a new per‑mailbox capability that transfers the Source of Authority (SOA) for Exchange attributes to the cloud. Flip a switch (IsExchangeCloudManaged) and you can manage aliases, GAL visibility, custom/extension attributes, and many mailbox flags directly in Exchange Online for directory‑synced users—without keeping an on‑prem Exchange server (or …