This message is related to moving (offboarding) users who have auto expanding archive enabled from exchange online to on-premises servers.
When this will happen
Preview: We will begin rolling out mid-November 2022 and expect to complete by late November 2022
Standard Release: We will begin rolling out mid-December 2022 and expect to complete it by late December 2022
How this will affect your organization
For Exchange Online users who have auto expanding archives enabled, we will block offboarding/moving their mailboxes to on-premises. This is because offboarding/moving content from auto-expanding archives is not a supported feature today. Please see details in the public documentation regarding Enable auto-expanding archiving. To quote “Auto-expanding archiving is supported for cloud-based archive mailboxes in an Exchange hybrid deployment for users who have an on-premises primary mailbox. However, after auto-expanding archiving is enabled for a cloud-based archive mailbox, you can’t off-board that archive mailbox back to the on-premises Exchange organization. Auto-expanding archiving isn’t supported for on-premises mailboxes in any version of Exchange Server.”
What you need to do to prepare
Mailbox migrations to on-premises from auto expanding archives is not supported. Any on-going migrations will fail. The change we are putting out is to fail early and gracefully with no data loss by adding a check whether the auto-expanding archive exists for a user.
Message ID: MC467234
Platform: Online, World tenant