Due to overzealous filtering on Microsoft’s side, some emails to Outlook and Hotmail addresses may not be delivered. If you’re affected, please use a different email address or try again later.
If you have an antivirus installed, google how to add the exception.
Otherwise, you have to add that to default windowns antivirus. Tutorial here: https://support.microsoft.com/en-us/windows/add-an-exclusion-to-windows-security-811816c0-4dfd-af4a-47e4-c301afe13b26