Some users may not be able to access Exchange Online via Outlook on the web

Final status: Microsoft has confirmed that deployment of the fix has completed, and impact has been mitigated.

Current status: The fix has reached over half of the affected infrastructure and we're seeing a significant decrease in failure rates. Microsoft expects that most users will experience relief within the next 60 minutes.

Estimated time to resolve: Microsoft anticipates most users will experience resolution by 9:00 PM UTC.

Next update by: Tuesday, June 27, 2023 at 4:00 PM CDT

Current status: We've initiated our deployment of the fix, and users should experience incremental relief as the fix progresses. We're closely monitoring the deployment to ensure that the service recovers as expected and we'll provide an estimated timeline when available.

Next update by: Tuesday, June 27, 2023 at 3:00 PM CDT

Current status: Microsoft has determined that re-applying the updated build on a limited scale has not resulted in service recovery as expected. While Microsoft is investigating this outcome, they are focused on alternate mitigation options to resolve the issue as quickly as possible.

Preliminary root cause: Microsoft suspects that a configuration issue within a recent service build is causing impact.

Next update by: Tuesday, June 27, 2023 at 12:00 PM CDT

Current status: Microsoft has isolated the components within the affected build, so they can further investigate diagnostic data and establish a fix to mitigate the impact.

Next update by: Tuesday, June 27, 2023 at 10:00 AM CDT

User impact: Users in North America may be unable to access their Exchange Online mailbox using Outlook on the web.

More info: Affected users may encounter an unexpected 500 error when accessing Outlook on the web.

Current status: We've determined that a recent system update to the Exchange Online service may have caused an impact. This update has now been stopped while we review diagnostic logs to explore mitigation options for the components that have already received this update.

Next Update: Tuesday, June 27, 2023 at 9:00 AM CDT (21076971)