Mail not working in windows 10 However, there'll be times once you may encounter some issues, like e-mails not syncing, problems opening the app, adding new e-mail accounts, and individual settings not working. While the matter usually is often traced to a misconfiguration of an account, it could even be a problem with the Mail app itself.If you're having syncing and other issues with the built-in Mail app, you'll use Power Shell to uninstall and reinstall the e-mail app using the shop, but this might be a tedious process for everyday users. Thankfully, Windows 10 now includes a reset choice to fix any issues with the app without having to reinstall them.In this guide, you'll learn the straightforward steps to reset the Mail app on Windows 10 to repair any issues.