How to track messages from Facebook API

I´m trying to track messages sent to my Facebook friends.

For example: I sent a message to James Bond, how do I开发者_Go百科 know if he read it or not?

The Facebook Graph API does not support this yet - http://developers.facebook.com/docs/reference/api/message/. I suspect this is because there is no guaranteed way to see if a message has been read or not based on how the user accesses their messages.

It would also require permission tokens to be passed in a three-legged (recipient to application, recipient to sender) verification.