Summary
After you install the May 2025 Hotfix Update (HU) for Microsoft Exchange Server 2019 and 2016, you can't access the archived mailboxes that are hosted in the cloud through Outlook on the Web (OWA). This issue occurs because of the retirement of cloud archive mailboxes. When you try to access an archived mailbox that's hosted in Exchange Online through OWA, you receive the following error message:Â
Accessing an archive mailbox hosted in Exchange Online via OWA is no longer supported. Please use the Outlook Desktop client instead.
For more information about the retirement of cloud archive mailboxes, see Retirement of cloud archive mailbox access by using Exchange Server on-premises OWA.Â
