In May, we announced the Public Preview of Writeback for Cloud-Managed Remote Mailboxes. Since then, many customers have enabled this feature and shared their feedback. Today, we're excited to announ...
Published Aug 03, 2026
Version 1.0
Blog Post
We've used the IsExchangeCloudManaged parameter to move Exchange attribute SOA as described in the documentation. Editing Exchange attributes via the Exchange Online Admin Center or Exchange Online PowerShell immediately works as expected.
The documentation (and blog posts here) explicitly mention that management via the Microsoft 365 Admin Center should also be possible:
"After moving the SOA for Exchange attributes to the cloud, these details can be managed using EXO PowerShell, the Microsoft 365 Admin Center, or the Exchange Admin Center, whereas identity attributes are still modified through on-premises Active Directory only."
However, for our environment this does not seem to be the case.
E.g. when trying to add another alias address ("proxyAddresses") to an existing mailbox via the Microsoft 365 Admin Center, it shows the same "User is synchronized with on-premises AD. Some attributes can only be edited on-premises." hint (loosely translated as I currently just have the german translation of that message at hand) and for example the "Add" button stays greyed out.
Is this to be expected?
kumarmukeshMicrosoft
Thanks for sharing this. We will be sharing the same to concerned team.
And this would still work in EAC and EXO powershell.