templates/xnewsletter_letter_preview.tpl
<{include file="db:xnewsletter_header.tpl"}>
<div style='clear:both;'></div>
<h2><{$letter.letter_title}></h2>
<div style='padding:10px;margin:20px 0;border:1px solid black;'>
<{$letter.letter_content_templated}>
</div>
<div style='clear:both;'></div>
<input class="btn btn-primary wg-color1" type="button" value="<{$smarty.const._BACK}>" onclick="history.go(-1);">
<div style='clear:both;'></div>
<{include file="db:xnewsletter_footer.tpl"}>