I recently updated my email thunderbird account and it is not working as it should any more: sometimes it won't delete messages or won't send a message or refuses to close or will not open or opens only with one email which I then am unable to close or minimise -in short it is unreliable and mad and becoming unusable and I don't see how to correct it- My security system seems unable to detect any problem. Do you think I uploaded a scam instead of a true update version?