It looks like a very specific setting of $email to the short code name ‘your-email’ from CF7 seems to be the culprit here:
Line 406 email-before-download.php
$email = $cf7->posted_data[‘your-email’];
//compare email againts not allowed domains.
$forbidden_domains = get_option(’email_before_download_forbidden_domains’);
$domains = explode(‘,’, $forbidden_domains);
Then again at: 525
$link_data[’email’] = $cf7->posted_data[‘your-email’];
which causes the insert at line 528 to fail
$wpdb->insert( $table_link, $link_data );
So the download mapping is not properly passed to the user.