10 Mail App not working....
have had a few people complaining about emails not syncing, Mail
app not opening and problems adding new email accounts.
10 mail app has some known problems and simply resetting the app
can often resolve these issues.
problems can be repaired by using the following the steps.
How to reset the Mail app Settings
Apps & Features
the Mail and Calendar app from the list
on Advanced options
Mail app should work fine, if not try one of the solutions below...
How to uninstall the Mail app on Windows 10 (advanced users)
start button and select Windows PowerShell
and select Run as administrator
& Paste: Get-AppxPackage Microsoft.windowscommunicationsapps
How to reinstall the Mail app on Windows 10
Windows Store and search for Mail and Calendar and click install.
How to install missing Mail app packages on Windows 10 (advanced
CMD in search box and right-click Command Prompt and click Run
and Paste: dism /online /Add-Capability /CapabilityName:OneCoreUAP.OneSync~~~~0.0.1.0
your computer and mail app should be working fine now.