Windows Live Mail fails after Win10 Update

1. Close WLM
2. Run Regedit
   
3. Go to: Computer\HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\WINDOWS LIVE MAIL
4. Either create or modify these 3 DWORD entries:
   1. ​RecreateFolderIndex
         DWORD = 1
      
   2. RecreateStreamIndex
         DWORD = 1
      
   3. RecreateUIDIndex
         DWORD = 1
5. ​Start WLM and check mail - it should be working now.
   

Source: https://www.tenforums.com/browsers-email/162878-windows-live-mail-will-no-longer-send-receive-emails.html?s=9c7cdd0d692b835373dc360df8ef33c3