Users are unable to access Microsoft 365 services in South America

A post-incident report has been published.

A post-incident report has been published.

A post-incident report has been published.

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users were unable to access Microsoft 365 services. More info: Users may have experienced email delivery delays. intermittent connection disruptions, and encountered service unavailability (503) errors when connecting to Outlook and Microsoft Teams. Additionally, users may have been unable to access SharePoint sites and OneDrive content. Final status: Service availability has returned to pre-incident thresholds and users are no longer impacted by this issue. Scope of impact: Some users in South America attempting to access Microsoft 365 services may have been impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC End time: Wednesday, May 13, 2026, at 4:30 PM UTC Preliminary root cause: Network connectivity issues resulting from a damaged fiber cable caused certain network paths to become unstable. This was further exacerbated by an influx in traffic being routed through alternate paths. Next steps: We're examining our failover mechanisms so we can identify areas for more effective traffic rerouting duration during future connectivity issues. We're still performing a detailed internal post-mortem of the issue. We're providing up to date details in the current Post Incident Report but will be providing further details in an updated Post Incident Report provided by Friday, May 29, 2026.

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays. intermittent connection disruptions, and encounter service unavailability (503) errors when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: The vast majority of users are no longer affected by this event. We're continuing to employ infrastructure optimizations to address full resolution for any users still residually affected. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 8:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays. intermittent connection disruptions, and encounter service unavailability (503) errors when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: While the service remains stable for the majority of users, we’re taking steps to further manage traffic and reduce demand on portions of the service that are experiencing high load. By optimizing how data is processed, we’re working to stabilize performance across the environment. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 7:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays. intermittent connection disruptions, and encounter service unavailability (503) errors when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: We’re actively redirecting traffic to healthy infrastructure to further reduce impact and improve service performance. We’re continuing to monitor the environment as these changes take effect. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 6:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays. intermittent connection disruptions, and encounter service unavailability (503) errors when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: Our telemetry indicates that service has recovered for the majority of users, and we’re continuing our work to ensure long-term stability across the affected infrastructure. To that end, we’re bringing an additional network route online and making adjustments to traffic flow to help improve connectivity to the remaining impacted service segment. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 5:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays and intermittent connection disruptions when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: We’ve confirmed that many users are now experiencing relief as a result of our mitigation actions; however, high demand on a portion of infrastructure we routed traffic through may be resulting in residual impact to some users. We’re adding additional resources to this infrastructure and are continuing to monitor for recovery. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 5:00 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays and intermittent connection disruptions when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: We’ve identified a fiber connectivity disruption between regions in South America impacting service availability. Traffic has been rerouted to alternate network paths, and we're continuing to monitor the environment to ensure service is restored. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Start time: Wednesday, May 13, 2026, at 1:30 PM UTC Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 4:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays and intermittent connection disruptions when connecting to Outlook and Teams. Additionally, users may be unable to access SharePoint sites and OneDrive content. Current status: We’re taking mitigative actions which include bringing affected network paths back online and redirecting traffic to healthy network infrastructure. We’re continuing to monitor the impact and working to restore service while further isolating the underlying cause. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Preliminary root cause: Intermittent network connectivity issues are causing certain network paths to become unstable, resulting in increased traffic being routed through alternate paths and leading to impact. Next update by: Wednesday, May 13, 2026, at 4:00 PM UTC

We've identified a network connection issue in South America affecting connections for users hosted primarily in that region. We're working to bring additional network resources online to mitigate impact. This quick update is designed to give the latest information on this issue.

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: Users may experience email delivery delays and intermittent connection disruptions when connecting to Outlook, Teams, and other Microsoft 365 services. Current status: We’re examining network health and investigating errors observed in internal telemetry to isolate the root cause and determine our next steps. Scope of impact: Some users in South America attempting to access Microsoft 365 services may be impacted. Next update by: Wednesday, May 13, 2026, at 3:30 PM UTC

Title: Users are unable to access Microsoft 365 services in South America User impact: Some users are unable to access Microsoft 365 services. More info: User reports indicate that impact is primarily to Outlook, though other Microsoft 365 services and features may be affected. Current Status: We are aware of an emerging issue where some users are unable to access Microsoft 365 services. We are investigating the issue and will provide another update within the next 30 minutes.