Jeremy Herve on "[Plugin: Jetpack by WordPress.com] Change e-mail address to which e-mails via contact form are sent"

You can choose where the emails are sent when building the form, in the "Email Notifications" tab, as shown here:
http://jetpack.me/support/contact-form/#jp-carousel-723

Once you've entered your email address there, click on "Save and go back to the form builder", and then click to insert the updated form to your page.