11.12.26 – 2:50PM – Update:
From Microsoft
We’re testing a configuration change to address a problem that’s causing servers to fail automated health checks and become unavailable. In parallel, we’ve initiated a restart of all affected servers and are monitoring health as they return to service.
11.12.26 – 2:30pm – Update:
From Microsoft
We determined the elevated load isn’t driven by an increase in traffic, but by a number of servers being unexpectedly unavailable; straining the remaining infrastructure. We’re working to safely return them to service.
11.12.26 – 2:15pm – Update:
From Microsoft
We’re aggressively pursuing all pathways to reduce impact. We’ve paused all deployments, we’re moving additional traffic off the affected infrastructure, and we’re restarting affected servers to return them to service.
11.12.26 – 1:56pm – Update:
From Microsoft (Tweet)
We’ve begun redistributing connection traffic across our broader worldwide infrastructure to help balance the load.
11.12.26 – 1:52pm – Update:
Microsoft added the following services impacted on their end:
– Exchange Online
– Microsoft Teams
– SharePoint Online
– Microsoft Copilot 365
– Microsoft Defender XDR
Microsoft updated their current status:
Current status: We’re investigating an issue impacting multiple Microsoft 365 services and we’ve determined the affected infrastructure is experiencing elevated load across multiple regions, which is likely contributing to the connectivity errors. We’re restarting and repairing impacted portions of this infrastructure to restore capacity, and reviewing an unexpected increase in a specific type of service traffic to determine whether it’s contributing to the elevated load. In parallel, we’re evaluating options to redirect traffic to alternate infrastructure to expedite relief.
11.12.26 – 1:43pm – Update:
From Microsoft (Tweet):
We’ve determined a portion of infrastructure is experiencing elevated load across multiple regions, which is likely contributing to the connectivity errors. We’re providing more information under EX1550543 and MO1550821 in the Microsoft 365 admin center, as well as status.cloud.microsoft
ORIGINAL STORY
11.12.26 – 1:30pm: We are seeing an uptick of reports of outages for the following services:
Outlook
Sharepoint
One Drive
Co-Pilot
Teams
& More
Microsoft is aware of the issue and is currently investigating.
Error: EX1550543
From Microsoft:
User impact: Users may be unable to connect to their mailboxes in Exchange Online through multiple connection methods.
More info: Potentially impacted connection methods may include:
– Outlook on the web
– Messaging API (MAPI)
– Exchange ActiveSync (EAS)
– Representational State Transfer (REST) API
Current status: We’ve identified connectivity errors occurring on a portion of Exchange Online infrastructure which receives and processes users’ access requests. We’ve collected networking logs to review to further investigate the source of these errors and confirm our next steps.
Scope of impact: This issue may affect users attempting to access their mailbox in Exchange Online using the affected connection methods.
Tweet: We’re investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.