We bought a new laptop and a new desktop with Windows 8.1 in Jan/15.  I loaded Windows Live Mail 2012 on both machines.  

Since then WLM periodically looses our email folders and then re-downloads our mail from our email provider; 5 times this year on the laptop and twice this year on the desktop.  Why?  And it's not Windows 8.1 fault because there are numerous postings about this issue from users with Windows 7 and Vista.  

I now know how to recover the lost folders, (when this happens WLM sets up a Recovery folder).  

What I want to know is why is WLM losing the folders in the first place?  How can it be fixed so it doesn't lose the folders?