Taken from https://status.office365.com/
Start time: November 20, 2019, at 1:13 AM UTC
Next update by: November 20, 2019, at 2:30 AM UTC
Current status: We've identified a problem that may be preventing customers from accessing the Microsoft 365 admin center and multiple services. We’re working to restore access to all services and we'll provide more information when we’ve isolated the root cause.
-Microsoft Service Health
It appears that Office 365 web portals and all service relying on an internet connection to function are currently inoperable. We are seeing outages on Teams, Onedrive and Mail. We will keep this page updated with any changes.