We are retiring a feature in Exchange Online that previously enabled users with a primary mailbox hosted on Exchange Server (on-premises) to access their archive mailbox, hosted in Exchange Online, via Outlook on the Web (OWA). This change will solely impact OWA usage and does not affect access to the archive mailbox using other supported Outlook clients.
Imagine the following situation: An Exchange Server hybrid environment is in place, with some mailboxes hosted on Exchange Server. Among these, certain mailboxes have activated a cloud archive, meaning their archive mailboxes are hosted in Exchange Online. Up until now, users could access these archive mailboxes via Outlook on the Web (OWA). However, starting May 12, 2025, this access will no longer be available. Users will still be able to access their archive mailboxes through Outlook Desktop.
We’ve identified all customers who have used this workflow in the last 30 days. If your organization is affected by this change, you should see a Message Center post MC1053644 posted in your Microsoft 365 admin center. If you’re using this workflow but don’t see the message center post, please reach out to us via exchonpremfeedback[AT]microsoft.com and let us know.
The Exchange Team
Microsoft