Lost messages?

Hi! My message box was full recently, and 4 or 5 PMs were lost, is there anyway to retrieve them? I deleted my sent folder and now my pm box is not full anymore, but I wonder what the message said, if there is anyway to retrieve them, please tell, thanks!

 

If your mailbox was full, you would not receive any more messages because they could not be sent to you. They wouldn't be lost because they don't exist.