Currently, Email Notifications for WP Form Manager only allows forms to be emailed to user entries of the type 'text'. i have extended this to allow for sending to user entries of the type 'custom_list', by making the following simple edit ...
Change Line 164 of pages/editformdesign.php from
<?php if($item['type'] == 'text'): ?>
<?php if($item['type'] == 'text' || $item['type'] == 'custom_list'): ?>
Note that you will want to ensure list values are valid email addresses of a following form:
email-address OR Label <email-address>