Check the mobile connection and Wi-Fi on your Windows 10.
Now, switch off the airplane mode if it is on.
Ensure that there is storage space available on Windows 10 devices.
Along with it, recheck the POP or IMAP configuration settings.
If the browser is compatible and Cox email is not responding, you should clear the browser data like cookies, cache, etc.
If you face any issue with Cox email not sending on Windows 10, turn off the third-party extensions and add-ons installed on the browser. You should disable these add-ons one by one to identify which add-on is problematic.
These are the steps you need to perform to smoothly deal with the Cox email not sending on Windows 10.