discourse/app/assets/javascripts/admin/addon/templates/email-index.hbs

<table class="table">
  <tbody>
    <tr>
      <th>{{i18n "admin.email.delivery_method"}}</th>
      <td>{{delivery_method}}</td>
    </tr>

    {{#each model.settings as |s|}}
      <tr>
        <th style="width: 25%">{{s.name}}</th>
        <td>{{s.value}}</td>
      </tr>
    {{/each}}
  </tbody>
</table>

<form>
  <div class="admin-controls">
    {{#if sendingEmail}}
      <div class="controls">{{i18n "admin.email.sending_test"}}</div>
    {{else}}
      <div class="controls">
        {{text-field value=testEmailAddress placeholderKey="admin.email.test_email_address"}}
      </div>
      <div class="controls">
        {{d-button
          class="btn-primary"
          action=(action "sendTestEmail")
          disabled=sendTestEmailDisabled
          label="admin.email.send_test"
          type="submit"}}
        {{#if sentTestEmailMessage}}<span class="result-message">{{sentTestEmailMessage}}</span>{{/if}}
      </div>
    {{/if}}
  </div>
</form>