app/templates/emails/transactional/reply-must-use-personal-email.html

{% extends "base.html" %}

{% block content %}
  {{ render_text("Hi " + name) }}

  {% call text() %}
    We have recorded an attempt to send an email from your alias <b>{{ alias.email }}</b> using <b>{{ sender }}</b>.
  {% endcall %}

  {% call text() %}
    Please note that sending from this alias only works from one of these mailboxes: <br>
    {% for mailbox in alias.mailboxes %}
      - {{ mailbox.email }} <br>
    {% endfor %}
  {% endcall %}

  {% call text() %}
    Indeed only you can send emails on behalf of your alias.
  {% endcall %}

  {% call text() %}
    Thanks, <br/>
    SimpleLogin Team.
  {% endcall %}

{% endblock %}