How Exchange Online Uses Archives to Offload Recoverable Items Storage

A change rolling out in mid-October will remove storage pressure on the Recoverable Items structure in Exchange Online mailboxes by offloading some data to archive mailboxes. The idea is a good one because it means that the storage allocated to Recoverable Items won’t fill up and require intervention so often. Users won’t know anything about what’s happening under the covers as it’s all hidden from view.

How to Find Exchange Online Archive Mailboxes Close to the New 1.5 TB Limit

A 1.5 TB limit applies to Exchange Online archive mailboxes from November 1, 2021. In this article, we use PowerShell to report how close expandable archives are to the new limit. In reality, not many archive mailboxes will approach the new limit, but it’s nice to know things like the daily growth rate for an archive and how many days it will take for an archive to reach 1.5 TB. All whimsical stuff calculated with PowerShell!