CCleaner and Thunderbird

[bisnuto]

I have used CCleaner on a windows 10 computer, and it cleared all the mail box from Thunderbird email application.

I learned that to avoid this problem, Thunderbird must be unchecked on CCleaner. I read on many forums that the mails were gone forever, however a I found some old data, and realize that I could recover the old e-mail messages.

Finally, I was able to recover the Thunderbird email box, by rewriting the content of the user profile's prefs.js, using Invalidprefs.js content. 

I want to check the fackts about this problem and be completely sure of what have happened:

1- CCleaner reseted the user profile's prefs.js, messing with the e-mail data preferences.

2-The old e-mail messages data remains untouched, but cant be read, because of the reseted user preferences

Can someone confirm it please?