See my response, https://jfw.groups.io/g/main/message/81639, last night on another topic on this very forum.

It is clear that for Windows 10 users we have entered the stage where Windows Live Mail 2012 (and almost certainly all earlier versions, too) is no longer going to work reliably.

Now is the time to transition to a supported e-mail client of your choosing or webmail (and most webmail can now handle multiple accounts, and accounts that are outside of the webmail itself, e.g., Gmail webmail lets you set up yahoo.com, outlook.com, etc., accounts for reading inside their webmail interface).
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Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041  

The purpose of education is not to validate ignorance but to overcome it.
       ~ Lawrence Krauss