Some users may be unable to view mailbox storage data in Outlook and Outlook on the web

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may have been unable to view mailbox storage data in Outlook and Outlook on the web. More info: Affected users were shown the error message, "Storage data is temporarily unavailable," when trying to view mailbox storage data for multiple mailboxes. Final status: We've validated that our code fix has fully deployed throughout the affected environments and has successfully remediated all impact. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may have been impacted. Start time: Sunday, July 12, 2026, at 12:00 AM UTC End time: Wednesday, July 22, 2026, at 12:00 AM UTC Root cause: A recent service build introduced an unsupported property into mailbox statistics data returned by a backend process. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed, which resulted in impact. Next steps: - We're reviewing our service build validation and implementation processes to improve how we detect potential unsupported properties and prevent similar mailbox storage data issues from occurring in the future. This is the final update for the event.

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may be unable to view mailbox storage data in Outlook and Outlook on the web. More info: Affected users are shown the following error message "Storage data is temporarily unavailable" when trying to view mailbox storage data for multiple mailboxes. Current status: Our fix has completed approximately 94 percent of its deployment within the affected environment, and our timeline projects it will have completed and that the impact will be remediated by our next scheduled communication update. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may be impacted. This information may be updated as our investigation continues. Root cause: A recent service build introduced an unsupported property into mailbox statistics data returned by a backend process. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed. Next update by: Thursday, July 23, 2026, at 7:00 PM UTC

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may be unable to view mailbox storage data in Outlook and Outlook on the web. More info: Affected users are shown the following error message "Storage data is temporarily unavailable" when trying to view mailbox storage data for multiple mailboxes. Current status: We've completed validation and initiated the release of the fix. Currently at approximately 30 percent, we're monitoring as it progresses and expect to have a complete remediation timeline by the next scheduled update. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may be impacted. This information may be updated as our investigation continues. Root cause: A recent service build introduced an unsupported property into mailbox statistics data returned by a backend process. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed. Next update by: Monday, July 20, 2026, at 7:00 PM UTC

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may be unable to view mailbox storage data in Outlook and Outlook on the web. More info: Affected users are shown the following error message "Storage data is temporarily unavailable" when trying to view mailbox storage data for multiple mailboxes. Current status: We're continuing to validate our code fix as it’s being deployed through our internal test environment and monitor service telemetry before proceeding with deployment to the affected environments to help ensure successful remediation. Once available, we'll provide a resolution timeline. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may be impacted. This information may be updated as our investigation continues. Root cause: A recent service build introduced an unsupported property into mailbox statistics data returned by a backend process. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed. Next update by: Friday, July 17, 2026, at 7:00 PM UTC

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may be unable to view mailbox storage data in Outlook and Outlook on the web. More info: Affected users are shown the following error message "Storage data is temporarily unavailable" when trying to view mailbox storage data for multiple mailboxes. Current status: We've identified that a recent service build introduced an unsupported property into mailbox statistics data. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed. We've deployed a code fix to remove the unsupported property and are monitoring service telemetry to verify its success in fixing the issue. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may be impacted. This information may be updated as our investigation continues. Root cause: A recent service build introduced an unsupported property into mailbox statistics data returned by a backend process. When the service attempted to retrieve mailbox storage information, the unsupported property caused the request to fail and prevented mailbox storage data from being displayed. Next update by: Wednesday, July 22, 2026, at 1:30 PM UTC

Title: Some users may be unable to view mailbox storage data in Outlook and Outlook on the web User impact: Users may be unable to view mailbox storage data in Outlook and Outlook on the web. More info: Users are shown the following error message "Storage data is temporarily unavailable" when trying to view mailbox storage data for multiple mailboxes. Current status: We're reviewing support case details to determine our next troubleshooting steps. Scope of impact: Some users attempting to view mailbox storage data in Outlook and Outlook on the web may be impacted. This information may be updated as our investigation continues. Next update by: Wednesday, July 15, 2026, at 1:30 PM UTC