Writeback for Cloud-Managed Remote Mailboxes is now Generally Available!

📬 Writeback for Cloud-Managed Remote Mailboxes is now Generally Available!

Microsoft has reached another milestone in simplifying Exchange Hybrid management. Writeback for Cloud-Managed Remote Mailboxes is now generally available, allowing organizations to manage Exchange-specific attributes for synchronized users directly in Exchange Online while automatically writing those changes back to on-premises Active Directory.

🚀 What's new?

Organizations can now transfer the Source of Authority (SOA) for Exchange attributes to the cloud, making Exchange Online the primary management interface for supported mailbox attributes.

After the SOA has been moved, administrators can manage Exchange attributes using:

✅ Exchange Online PowerShell ✅ Exchange Admin Center (EAC) ✅ Microsoft 365 Admin Center

Changes are then automatically synchronized back to on-premises Active Directory using Microsoft Entra Cloud Sync, helping keep both environments aligned.

🔑 What stays on-premises?

Identity management remains unchanged.

Core identity attributes—including users, groups, and authentication-related properties—continue to be managed through on-premises Active Directory.

💡 Why this matters

For many hybrid organizations, Exchange attributes have traditionally been managed on-premises simply because applications still depended on Active Directory.

With Exchange attribute writeback, administrators can confidently manage mailbox attributes in the cloud while ensuring on-premises applications continue receiving up-to-date information. It's another important step toward reducing reliance on the last Exchange Server without disrupting hybrid environments.

Learn More: https://learn.microsoft.com/en-us/exchange/hybrid-deployment/enable-exchange-attributes-cloud-management