PHP script to check MS Outlook version

Hi, I'm looking for PHP script to detect which version of MS Outlook that is use to open the email. The script will be embedded via image source link. It should be a really small script but it's much harder than it sounds. I hired a freelance prior to this post but he couldn't complete. So please make sure that you know how before bidding. I will only pay after I have tested the script to be working correctly and give the correct result. Sorry, had a very very bad experience with the previous freelance from another freelance web.