Using the New Outlook for Mac for personal email and calendar
Hello!
This is Tin, I'll do my best to help you. May I know how do you access your account? Do you use the app or a browser for this? Please try to access your account https://outlook.live.comusing this link and see if you can send or receive emails from there.
If yes, and the issue only happen to your application, please try to sign out and sign back in your account from there, mostlikely its just a syncing issue.
I look forward to your feedback.
Best regards,
Tin