I tried all of these. Nothing worked. Even a fresh install with current updates. Gmail already had IPOP and IMAP enabled. Option 2 and 3 from a 4-year old video did the trick. I had already tried the first option as that is what a Microsoft forum suggested with no luck.

1. How to reset the Mail app Settings

   • Click Start button
   • Settings.
   • Click Apps.
   • Click Apps & Features.
   • Select the Mail and Calendar app from the list.
   • Click on Advanced options.
   • Click Reset button.

2. How to uninstall the Mail app on Windows 10

   • Right-click start button and select Windows PowerShell, right-click and select >Run as administrator.
   • Copy & Paste: Get-AppxPackage Microsoft.windowscommunicationsapps | Remove-AppxPackage

3. How to reinstall the Mail app on Windows 10

   • Open Windows Store and search for Mail and Calendar and click install.

4. How to install missing Mail app packages on Windows 10

   • Type CMD in search box and right-click Command Prompt and click Run as >administrator.

   • Copy and Paste: dism /online /Add-Capability /CapabilityName:OneCoreUAP.OneSync~~~~0.0.1.0

   • Reboot your computer and Mail app should be working fine now.

source: https://www.youtube.com/watch?v=k39Rq4q91mw (video description)

I tried all of these. Nothing worked. Even a fresh install with current updates. Gmail already had IPOP and IMAP enabled. Option 2 and 3 from a 4-year old video did the trick. I had already tried the first option as that is what a Microsoft forum suggested with no luck.

1. How to reset the Mail app Settings

   • Click Start button
   • Settings.
   • Click Apps.
   • Click Apps & Features.
   • Select the Mail and Calendar app from the list.
   • Click on Advanced options.
   • Click Reset button.

2. How to uninstall the Mail app on Windows 10

   • Right-click start button and select Windows PowerShell, right-click and select >Run as administrator.
   • Copy & Paste: Get-AppxPackage Microsoft.windowscommunicationsapps | Remove-AppxPackage

3. How to reinstall the Mail app on Windows 10

   • Open Windows Store and search for Mail and Calendar and click install.

4. How to install missing Mail app packages on Windows 10

   • Type CMD in search box and right-click Command Prompt and click Run as >administrator.

   • Copy and Paste: dism /online /Add-Capability /CapabilityName:OneCoreUAP.OneSync~~~~0.0.1.0

   • Reboot your computer and Mail app should be working fine now.

source: https://www.youtube.com/watch?v=k39Rq4q91mw (video description)