Office 365 Email and Calendaring Service Interruption

Resolved

Service has been restored to Microsoft Outlook. Microsoft has confirmed that the global issue affecting Office 365 email and calendaring service has been resolved
Posted Sep 03, 2026 - 14:49 CDT

Update

Microsoft reports that, while monitoring service telemetry, it identified a small number of errors affecting mail flow. Microsoft is conducting targeted service restarts to reduce these errors and mitigate their impact. In parallel, Microsoft is continuing to analyze service health telemetry to determine whether any additional mitigation actions are required to fully restore normal functionality.

Northwestern Information Technology continues to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution. We will continue to monitor the situation and provide updates as new information becomes available.

The next update will be provided by 16:00 CDT.
Posted Sep 03, 2026 - 11:47 CDT

Update

Microsoft reports that service availability remains above 99 percent, and its monitoring shows the impact has been resolved for the majority of users. However, service restoration continues across the remaining affected infrastructure. We continue to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution.

We will continue to monitor services while awaiting Microsoft's confirmation that this incident is resolved.

The next update will be provided by 12:00 CDT, on Thursday, September 3.
Posted Sep 02, 2026 - 16:00 CDT

Update

Microsoft reports that service restoration continues across the affected infrastructure but has not yet provided an all-clear status for this incident. We continue to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution.

We will continue to monitor services while awaiting Microsoft's confirmation that this incident is resolved.

The next update will be provided by 16:00 CDT.
Posted Sep 02, 2026 - 11:35 CDT

Update

Microsoft reports that service restoration continues across the affected infrastructure but has not yet provided an all-clear status for this incident. We continue to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution.

We will continue to monitor services while awaiting Microsoft's confirmation that this incident is resolved.

The next update will be provided by 12:00 CDT on Wednesday, September 2.
Posted Sep 01, 2026 - 15:59 CDT

Update

Microsoft reports that service restoration is underway across the affected infrastructure but has not yet provided an all-clear status for this incident. We continue to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution.

We will continue to monitor services while awaiting Microsoft's confirmation that this incident is resolved.

The next update will be provided by 16:00 CDT.
Posted Sep 01, 2026 - 12:56 CDT

Update

Microsoft reports that service restoration is underway across the affected infrastructure but has not yet provided an all-clear status for this incident. We continue to see service restoration for affected services across the University, though some users may still experience intermittent issues as Microsoft works toward full resolution.

We will continue to monitor services while awaiting Microsoft's confirmation that this incident is resolved.

The next update will be provided by 13:00 CDT.
Posted Sep 01, 2026 - 10:43 CDT

Monitoring

Microsoft is reporting service restoration is underway across affected infrastructure but have not yet provided an all-clear status for this incident.

Northwestern Information Technology has monitored service restoration to our affected services as well and will continue to monitor while awaiting confirmation from Microsoft this incident is resolved.

Next update will be by 12:00 CDT
Posted Sep 01, 2026 - 08:16 CDT

Update

Microsoft continues working to resolve this issue as quickly as possible; however, we have not yet received a projected resolution time.

The next update will be provided by September 1, 2026 - 8:30 CDT,
Posted Aug 31, 2026 - 18:26 CDT

Update

Microsoft continues review of affected infrastructure and recent changes made to the service to definitively confirm the cause of impact. They continue to test and implement various mitigation strategies to apply the necessary authentication component, which have so far yielded positive results. They're monitoring these tests and mitigative actions closely and will provide an estimated time to resolution as soon as one is available.

The next update will be provided by 18:30 CDT.
Posted Aug 31, 2026 - 17:12 CDT

Update

Microsoft continues working to resolve this issue as quickly as possible; however, we have not yet received a projected resolution time.

The next update will be provided by 17:30 CDT.
Posted Aug 31, 2026 - 15:06 CDT

Update

Microsoft has identified a potential remediation and is performing tests to ensure its efficacy before applying it more broadly.

They also report additional services may be affected, including OneDrive, SharePoint, and Teams Calendaring.

The next update will be provided by 15:15 CDT.
Posted Aug 31, 2026 - 14:09 CDT

Update

The vendor has identified a potential corrective action for the affected infrastructure and is evaluating deployment options at this time.

The next update will be provided by 14:15 CDT
Posted Aug 31, 2026 - 13:11 CDT

Update

The vendor continues working to resolve this issue as quickly as possible; however, we have not yet received a projected resolution time.

The next update will be provided by 13:15 CDT.
Posted Aug 31, 2026 - 12:09 CDT

Identified

Northwestern Information Technology has identified an issue and Office 365 Email is unavailable.

While the vendor is working to resolve this issue as quickly as possible, we have not yet received a projected resolution time.

The next update will be provided by 12:15 CDT.
Posted Aug 31, 2026 - 11:10 CDT
This incident affected: Communication and Collaboration (Office 365 (Email and Calendaring)).