All emails sent are based on the Remindee’s template. So, using your own html template is not possible.
Remindee popups and email texts are 100% customizable, so they work with any language.
Each popup has its own email template associated. In this way, if you have popups in different languages for the same domain, you can customize your email for each language. It is worth noting that when you update your email
When your email quota is reached you have no more email credits, so remaining scheduled emails for the current month can not be sent. We recommend to upgrade for a plan that fits your needs (Pro plans include unlimited emails)