if they are not in any folder, you are not getting them. If you go to the post office and tell them the city sent me a mail and you have not got it, they sort of shrug their shoulders and suggest you get the city to look into it or mail you again. The same happens with email. The sender can chase through transmission logs and with help from the providers trace where an email goes. The recipient has no chance. One ting most people fail to understand about email, partially because of it reliability) is it is not guaranteed delivery. Your provider could simply refuse to accept email from any domain at any time and they do. It is called blacklisting. For instance gmail could refuse mail from Yahoo.