I would try exporting the game in HTML5 then zip it into a zip file, and send the zip file by email. They do accept HTML5 games, so I take it as they will be familiar enough with it to know what to do with the file and how to play it.
I've also just looke over the Kongregate sponsorship terms, and point 4 says :
"Kongregate-sponsored games must be released on Kongregate first [...]"
http://www.kongregate.com/pages/sponsorshipterms
Does that mean you should simply upload your game to Kongregat first, then ask for sponsorship? Then it'd be simple, you'd just have to send them a link to the game on Kongregate I guess.