changed

          <label class="col-xs-3 control-label">SMTP設定</label>
to
          <label class="col-xs-3 control-label">{{ t('app_setting.SMTP settings') }}</label>

lib/views/admin/app.html

@@ -94,7 +94,7 @@
         </div>
 
         <div class="form-group">
-          <label class="col-xs-3 control-label">SMTP設定</label>
+          <label class="col-xs-3 control-label">{{ t('app_setting.SMTP settings') }}</label>
           <div class="col-xs-4">
             <label for="">ホスト</label>
             <input class="form-control" type="text" name="settingForm[mail:smtpHost]"   value="{{ settingForm['mail:smtpHost']|default('') }}">