{% extends 'umessages/base_message.html' %}
{% load i18n umessages_tags %}
{% load url from future %}

{% block content_title %}<h2>{% trans "Messages" %}</h2>{% endblock %}

{% block content %}
{% get_unread_message_count_for user as unread_message_count %}
{% blocktrans %}{{ unread_message_count }} new messages.{% endblocktrans %}
<a href="{% url 'umessages_compose' %}">{% trans "Compose" %}</a>
<ul>
  {% for message in message_list %}
  <li>
  {% if message.from_user == user %}
  <a href="{% url 'umessages_detail' message.to_user.username %}">{{ message.to_user }}</a>
  {% get_unread_message_count_between user and message.to_user as unread_between_count %}
  {% else %}
  <a href="{% url 'umessages_detail' message.from_user.username %}">{{ message.from_user }}</a>
  {% get_unread_message_count_between user and message.from_user as unread_between_count %}
  {% endif %}
  {% blocktrans with message.latest_message as latest_message %}{{ latest_message }} ({{ unread_between_count }} new){% endblocktrans %}
  </li>
  {% endfor %}
</ul>
{% endblock %}

{% extends 'umessages/base_message.html' %}
{% load i18n umessages_tags %}
{% load url from future %}

{% block content_title %}<h2>{% trans "Messages" %}</h2>{% endblock %}

{% block content %}
{% get_unread_message_count_for user as unread_message_count %}
{% blocktrans %}{{ unread_message_count }} new messages.{% endblocktrans %}
<a href="{% url 'umessages_compose' %}">{% trans "Compose" %}</a>
<ul class="messages-list">
  {% for message in message_list %}
  <li>
  {% if message.from_user == user %}
  <a href="{% url 'umessages_detail' message.to_user.username %}">{{ message.to_user }}</a>
  {% get_unread_message_count_between user and message.to_user as unread_between_count %}
  {% else %}
  <a href="{% url 'umessages_detail' message.from_user.username %}">{{ message.from_user }}</a>
  {% get_unread_message_count_between user and message.from_user as unread_between_count %}
  {% endif %}
  {% blocktrans with message.latest_message as latest_message %}{{ latest_message }} ({{ unread_between_count }} new){% endblocktrans %}
  </li>
  {% endfor %}
</ul>
{% endblock %}

Add messages-list class to ul
Add messages-list class to ul
