I partially solved my problem deleting manually a lot of sent items untill I had no more virus.
So, I still do not know how to restore the folder, in case of a new e-mail virus, if Avast behavior will still be the same - removing all the folder to Quarantine.
I tried to scan Avast with opened files, as suggested VLK, but I couldn't do that, because the Menu Default for the files is - blocked (that's how it is marked in the porguese version of the programm I have).
As I have a free version of Avast 4,6, could it be the reason for me not being allowed to change this status or is there something I did wrong or I simply did not do?
I thank any help.
Regina