I am attempting to make a custom template for my Commerce Email emails. CE uses Variable Email and HTMLMail. I have put the template (named htmlmail--variable_email--custom_email_order.tpl.php) into the root of my theme folder. Nothing. The test htmlmail template is in the same place and works fine. I have cleared caches on the performance and in PHPMyAdmin, and run cron. Still doesn't work. Is this peculiar to Variable Email or HTMLMail?