Sending, receiving, and organizing email in Outlook.com
Is this issue started today or yesterday? If so, Microsoft is currently experiencing a service disruption affecting Outlook and other Microsoft services. The issue is on Microsoft's end, so there is nothing you need to do on your device or account for now. I recommend waiting until Microsoft resolves the issue and normal service is restored.
You can follow the latest updates through the official channels below:
Microsoft Service Status: https://status.cloud.microsoft/
Microsoft 365 Status on X: https://x.com/MSFT365Status/status/2120938282204688468