Problem transferring sent emails to a new computer

Greetings,

I apologize in advance for asking a question that may seem trivial or simple, but I am at a loss.  Here is the situation.  I recently got a new computer, and over Christmas my son set it up (yes, he's far more competent than I am).  He networked the old computer and the new computer to facilitate the transfer of files.  My email account is with frontier.com, but I use Windows Live Mail.  I don't know what the WLM version is on the old computer, but my son set up the new computer with WLM Version 2012 (Build 16.4.3528.0331).  The WLM contacts did not transfer correctly, so I reloaded them manually into the new WLM address book.  My actual problem is that none of the sent emails got copied from the old computer to the new computer.  I tried to address this myself by using the export/import options.  I created a new folder on the desktop of the old computer and exported the sent emails to it.  Then I used the import option on the new computer to copy the sent emails into a new WLM storage folder.  It worked except for the fact that the addressees are all missing, which rather negates the point of the whole effort.  All of my searching for an answer to this problem has been in vain, and I would greatly appreciate any advice.  Thank you in advance for your time.

Regards,

Frustrated