Using classic Outlook for Windows in business environments
Hi @Donald Lim
Thank you for reaching out and sharing how critical this is for your business operations.
Microsoft has recently acknowledged an active service incident (MO1550821) involving connectivity issues across multiple Microsoft 365 services, including Exchange Online (which powers Outlook), Microsoft Teams, and SharePoint Online.
Because Microsoft's engineering team is currently actively investigating and working on a fix, there isn't an exact estimated time of restoration available yet. Here is how you can track real-time updates:
If you are a Microsoft 365 Admin: You can monitor the live status, root cause updates, and next scheduled update times directly in the Microsoft 365 Admin Center under Health > Service health (search for incident ID MO1550821).
If you are an end user: Please reach out to your organization's IT or Microsoft 365 administrator so they can track incident MO1550821 in the Admin Center and keep your team updated as soon as service is restored.
I understand how disruptive email downtime is for business communication, and Microsoft is treating this as a priority to get services back up as quickly as possible.