this topic demonstrates how to retrieve deleted messages from your facebook profile inbox. If you lost your old messages on facebook and for some reason you have to get them back for legal reason or because someone you love might be cheating on your. 
Sat Jan 17, 2009
can you show me how i can get back my deleted Facebook messages. i deleted some emails by mistake and now i need to retrieve them back because i had an important message from a friend. she is an old friend which i lost contact with and haven't spoken to her in a long time. now for legal reasons i have to contact her immediately because her husband might be cheating on her and want to see what we talked about so i can forward the email to my cousin so we can contact our family. this is urgent. please help you.
UPDATE: thanks for replying, i was able to get some messages back.