Add Product Attributes to Magento Order Email

default.phtml

        // File <yourtemplate>/email/order/items/order/default.phtml // 
        
        ....... 
        
        <?php /** Get product attributes  */ ?>
        <?php $_product = Mage::getModel('catalog/product')->load($_item->getProduct()->getId()) ?>
        <?php $_attributes = $_product->getAttributes() ?>
        <?php $_arrDisplayAttributes = array('of_attributes_display') ?>
        <?php foreach($_attributes as $_attribute) : ?>
            <?php $_attributeCode = $_attribute->getAttributeCode() ?>
            <?php if(in_array($_attributeCode, $_arrDisplayAttributes)) : ?>
                <?php if($_attribute->getFrontend()->getValue($_product) != '') : ?>
                    <dt><strong><em><?php echo $_attribute->getFrontend()->getLabel($_product) ?></em></strong></dt>
                    <dd style="margin:0; padding:0 0 0 9px;"><?php echo nl2br($_attribute->getFrontend()->getValue($_product)) ?></dd>
                <?php endif ?>
            <?php endif ?>
        <?php endforeach ?>
        <?php /**  // Get product attributes  */ ?>
        
        ......