check for bounced mails with php

I need to check whether mail is bounced mail or not.

There one library available which can do this. http://sourceforge.net/projects/bmh/

But my problem if as below:

1. Above library will open the actual mail box and fetch the bounced mails from it.
2. But in my case I have one text file in which source of the full email with header also. And I need to check for that particular mail not whole mailbox.
3. So how can I use that library with the normal text file, they have a functionality to check EML files stored in local drive but I don't want to use that, I just have to read the text from text file.

The email gets bounced to a mailbox, so you can't detect that it has bounced without reading that mailbox. You might be able to read your mail software's data files directly, but there is no guarantee your mail software won't change how it stores your files.