Microsoft Issues Urgent Warning Over Local Exchange Online Mailbox Moves

Neowin reports that Microsoft is actively discouraging IT administrators from using local mailbox moves inside the same Exchange Online tenant or datacenter.

Microsoft discourages IT admins from using New-MoveRequest command

Some admins rely on the New-MoveRequest PowerShell cmdlet to trigger these local moves. Microsoft says it never supported this scenario. The cmdlet still exists mainly for legacy reasons tied to on-premises Exchange Server 2010 workflows, not modern cloud deployments.

Microsoft explains that Exchange Online treats local mailbox moves as low-priority background operations. Engineers cannot easily troubleshoot them or accelerate completion, which means moves can take days. In some cases, admins risk creating orphaned or “dial-toned” mailboxes, especially if a move targets the wrong mailbox shard. Certain shard transitions can even orphan the primary mailbox due to how completion logic works.

The company stresses that Exchange Online already manages mailbox placement, load balancing, and performance automatically. Local moves do not fix mailbox corruption or boost performance, despite common misconceptions. For real issues, Microsoft urges admins to contact official support channels instead of attempting unsupported workarounds.

The New-MoveRequest cmdlet remains supported only for cross-tenant mailbox migrations, which explains why Microsoft has not removed it entirely.

While Exchange Online is not flawless, and it has issues, such as recent outages affecting IMAP access, Microsoft says it still offers greater reliability than risky manual mailbox moves. Stability and security are the priority for Microsoft, and this is why the company continues to harden email security by dropping legacy mail app support.

Meanwhile, competitors move forward as well, with Gmail expanding AI features through deeper Google Gemini integration.