discourse/plugins/chat/app/views/user_notifications/chat_summary.html.erb

<div class="summary-email">
  <table class="chat-summary-header text-header with-dir" style="background-color:#<%= @header_bgcolor -%>;width:100%;min-width:100%;">
    <tr>
      <td align="center" style="text-align: center;padding: 20px 0; font-family:Arial,sans-serif;">

        <a href="<%= Discourse.base_url %>" style="color:#<%= @header_color -%>;font-size:22px;text-decoration:none;">
          <%- if logo_url.blank? %>
            <%= SiteSetting.title %>
          <%- else %>
            <img src="<%= logo_url %>" height="40" style="clear:both;display:block;height:40px;margin:auto;max-width:100%;outline:0;text-decoration:none;" alt="<%= SiteSetting.title %>">
          <%- end %>
        </a>

      </td>
    </tr>
    <tr>
      <td align="center" style="font-weight:bold;font-size:22px;color:#0a0a0a">
        <%= I18n.t("user_notifications.chat_summary.description", count: @messages.size) %>
      </td>
    </tr>
  </table>

  <%- @grouped_messages.each do |chat_channel, messages| %>
    <%- other_messages_count = messages.size - 2 %>
    <table class="chat-summary-content" style="padding:1em;margin-top:20px;width:100%;min-width:100%;background-color:#f7f7f7;">
      <tbody>
        <tr>
          <td colspan="100%">
            <h5 style="margin:0.5em 0 0.5em 0;font-size:0.9em;"><%= chat_channel.title(@user) %></h5>
          </td>
        </tr>
        <%- messages.take(2).each do |chat_message| %>
          <%- sender = chat_message.user %>
          <%- sender_name = @display_usernames ? sender.username : sender.name %>

          <tr class="message-row">
            <td style="white-space:nowrap;vertical-align:top;padding:<%= rtl? ? '1em 2em 0 0' : '1em 0 0 2em' %>">
              <img src="<%= sender.small_avatar_url -%>" style="height:20px;width:20px;margin:<%= rtl? ? '0 0 5px 0' : '0 5px 0 0' %>;border-radius:50%;clear:both;display:inline-block;outline:0;text-decoration:none;vertical-align:top;" alt="<%= sender_name -%>">
              <span style="display:inline-block;color:#0a0a0a;vertical-align:top;font-weight:bold;">
                <%= sender_name -%>
              </span>
              <span style="display:inline-block;color:#0a0a0a;font-size:0.8em;">
                <%= I18n.l(@user_tz.to_local(chat_message.created_at), format: :long) -%>
              </span>
            </td>
          </tr>
          <tr>
            <td style="width:99%;margin:0;padding:<%= rtl? ? '0 2em 0 0' : '0 0 0 2em' %>;vertical-align:top;">
              <%= email_excerpt(chat_message.cooked_for_excerpt) %>
            </td>
          </tr>
        <%- end %>
        <tr>
          <td colspan="100%" style="padding:<%= rtl? ? '2em 2em 0 0' : '2em 0 0 2em' %>">
            <a class="more-messages-link" href="<%= messages.first.full_url %>">
              <%- if other_messages_count <= 0 %>
                <%= I18n.t("user_notifications.chat_summary.view_messages", count: messages.size)%>
              <%- else %>
                <%= I18n.t("user_notifications.chat_summary.view_more", count: other_messages_count)%>
              <%- end %>
            </a>
          </td>
        </tr>
      </tbody>
    </table>
  <%- end %>
</div>

<table class='summary-footer with-dir' style="margin-top:2em;width:100%">
  <tr>
    <td align="center">
      <%- if @unsubscribe_link %>
        <%= raw(t 'user_notifications.chat_summary.unsubscribe',
                site_link: html_site_link,
                email_preferences_link: link_to(t('user_notifications.chat_summary.your_chat_settings'), @preferences_path),
                unsubscribe_link: link_to(t('user_notifications.digest.click_here'), @unsubscribe_link)) %>
      <%- else %>
         <%= raw(t 'user_notifications.chat_summary.unsubscribe_no_link',
                site_link: html_site_link,
                email_preferences_link: link_to(t('user_notifications.chat_summary.your_chat_settings'), @preferences_path)) %>
      <%- end %>
    </td>
  </tr>
</table>