The Mail app email client in Windows 10 is the default email client in Windows 10. It was first introduced in Windows 8 and it has been improved dramatically in Windows 10. It doesn’t only supports Microsoft accounts but also other accounts as well.
If your Mail is not syncing your messages, not opened or showing an error, resetting the app might fix the issue.
Reinstalling the app is the best way to fix all the bugs and issues if you are facing any. However resetting is easier then reinstalling. When you reset the Mail app in Windows 10 using this method, it will delete your sign-in details and all saved data by Mail on your device.
Resetting Windows 10’s Mail app
* You must be running 14379 or later build of Windows 10 to reset apps.
Step 1: Open Settings.
Step 2: Click System.
Step 3: Click Apps and feature.
Step 4: Look for Mail and Calendar app entry and then click on the same to see Advanced options. Click Advanced options link.
Step 5: Click on the Reset button. When you see the confirmation dialog box, click Reset button again to clear all data and reset the Mail and Calendar app. Once the Reset is completed, you will see a check sign next to the Reset app.
Step 6: Launch the Mail app again, enter your email account credentials to sync your messages again.