app/templates/emails/transactional/verify-mailbox.html

{% extends "base.html" %}

{% block content %}
  {{ render_text("Hi " + user.name) }}
  {{ render_text("You have added "+ mailbox_email +" as an additional mailbox.") }}
  {{ render_text("To confirm, please click on the button below or use this link: <br> " + link) }}
  {{ render_button("Confirm email", link) }}
{% endblock %}