is Microsoft Outlook 365 currently down? I can't send/receive emails

Hi mimi thai-chen

Thank you for reaching out to Microsoft Q&A Forum and sharing this issue.

Based on my research, Microsoft has confirmed an ongoing service incident affecting Outlook/Exchange Online (Incident ID: EX1162980). A portion of their infrastructure responsible for mailbox connectivity is underperforming. As a result, some users are unable to send/receive messages or may see delayed delivery times and login errors. 

• The disruption began on October 1, 2025 (PST). Microsoft has since identified a configuration change related to the impact, reverted it, and restarted affected infrastructure. 
• Recovery is in progress, with service availability steadily improving. Messages that were delayed are now being processed, but it may take some time for the backlog to fully clear. 
• Microsoft is closely monitoring system health and updating customers via the official Service Health Dashboard.

For your reference: https://admin.microsoft.com/AdminPortal/Home#/servicehealth/:/alerts/EX1162980 

Note: Access is limited to Microsoft 365 Global Administrator. Please contact your IT admin if you don’t have access.  

At this stage, no action is required on your part. Once systems are fully restored, Outlook should begin functioning normally again without the need to make changes to your settings or devices. 

I understand how important reliable communication is to you, and I appreciate your patience while Microsoft engineers continue their work behind the scenes.

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