Dear user,
thanks for the compliments. We try to give our best.
The code you find in the csv file is the session code. The session lasts for the duration of the survey. To enter the e-mail you can create an e-mail field as a response and place it within your survey. You can make it mandatory, so the user is obliged to enter it.
Remember the user_id is empty for not logged users.
Best regards,
Perfect Survey Team