Using classic Outlook for Windows in business environments
I understand how frustrating this situation must be, especially when Outlook has been unavailable or experiencing issues for an extended period.
Based on your description, this issue appears to be related to Microsoft's ongoing service incident (Incident ID: MO1550821), which is affecting connectivity to multiple Microsoft 365 services, including Exchange Online, Microsoft Teams, and SharePoint Online.
According to Microsoft's latest update, Microsoft is continuing its mitigation efforts to address increased traffic between routing services and backend servers and improve service stability. However, the issue has not yet been fully resolved, and Microsoft has not provided a confirmed timeline for full service restoration.
- If you have Microsoft 365 administrator privileges, please sign in to the Microsoft 365 Admin Center using this link to view the details of this issue.
- If you are an end user: you can check the Microsoft 365 Service Status for the latest service availability updates.
Please kindly note that this is a user-to-user support forum, and I’m an end user just like you, not a member of the product team. As such, I’m unable to directly influence or expedite the resolution, nor can I provide a confirmed timeline for when the issue will be fully resolved and all services will return to normal. However, please rest assured that the relevant teams are working hard to resolve this issue as soon as possible.
Hopefully, Microsoft will restore the affected services soon. Thank you for your patience while Microsoft works to resolve the issue.