This support document should help you find out how to propose new translations for the Jetpack plugin:
http://jetpack.me/support/getting-started-with-jetpack/how-can-i-install-jetpack-in-my-language/
Since confirmation emails are sent from the WordPress.com servers, you'll want to look for the string to translate in the WordPress.com project:
http://translate.wordpress.com/projects/wpcom/
I hope this helps.