app/templates/emails/test-email.html

{% extends "base.html" %}

{% block content %}
  {{ render_text("Hi " + name + ",") }}
  {{ render_text("This is a test to make sure that you receive emails sent to your alias <b>" + alias + "</b>.") }}
  {{ render_text("If you have any questions, feel free to reply to this email.") }}
{% endblock %}