Copying Alex's response from your Contact Us form:
Yes, when JFBConnect creates a user account in Joomla, it will create it with the email address the user has on Facebook. That works for most of the social networks we support except Instagram, which doesn't support fetching the user's email address.
There are a few other social networks that don't support email fetching currently:
Amazon, Instagram, Meetup, VK.com
JFBConnect: store email from facebook account
