On Aug 20, 2025, we announced the Public Preview of Cloud-Managed Remote Mailboxes, a key step toward retiring the ‘last Exchange Server’ in your organization. The response from the community has bee...
Published Oct 15, 2025
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Is there still anything in play about the previously described Phase 1 and Phase 2?
kumarmukeshMicrosoft
So Phase 1 is the part of the feature that became generally available through this announcement.
And Phase 2 is mentioned as upcoming feature. We are about to start Private Preview of these features shortly.
"Upcoming featuresWe’re continuing to invest in features to help customers remove their dependency on Last Exchange Server.
- Tenant-Level LES Flag. Using this organization level setting, customers will be able to ensure that all new directory-synced mailboxes are synced as users in cloud (without Exchange attributes) and are cloud-managed by default. This will eliminate the need for per-mailbox configuration and will accelerate adoption. This feature will be available for Private Preview later this month, with planned GA next month.
- Writeback of Exchange Attributes. Customers will be able to opt-in for writeback of critical Exchange attributes (mentioned in the documentation) from the cloud back to on-premises Active Directory via Entra Cloud Sync. This feature is aimed to ensure smooth transition for organizations having LOB apps dependent on these critical attributes in on-premises AD to work seamlessly even after moving management to the cloud. This feature will be available for Private Preview in November with planned GA early next year.
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