app/views/layouts/mailer.html.erb
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>RailsCasts Weekly</title>
<style type="text/css">
body, td { color:#000000; font-size:14px; font-family:Verdana,Helvetica,Arial; }
.divider { background-color:#225079; height:4px; }
.layout h2 { margin-top:0; margin-bottom:8px; font-size:18px; }
.layout p { margin:8px 0; }
.layout img { border:solid 1px #777777; }
.layout .duration { font-size:11px;color:#555555; }
#footer { font-size:11px; color:#225079; }
#footer a { color:#225079;}
</style>
</head>
<body>
<table width="100%" id="background" border="0" cellpadding="0" cellspacing="0">
<tr><td align="center" valign="top">
<table width="650" id="main" border="0" cellpadding="0" cellspacing="20">
<tr>
<td id="header" colspan="2">
<!--a href="" width="423" height="56" alt="RailsCasts"></a-->
</td>
</tr>
<tr>
<td class="divider" colspan="4" bgcolor="#225079" height="4"></td>
</tr>
<tr class="layout">
<td>
<!--a href="#"><img src="" width="200" height="125" alt="#310 Getting Started with Rails"></a-->
</td>
<td valign="top">
<%= yield %>
</td>
</tr>
<tr>
<td class="divider" colspan="4" bgcolor="#225079" height="4"></td>
</tr>
<tr>
<td id="footer" colspan="2" align="center">
<p><a href="#">Unsubscribe</a> if you do not wish to receive these emails in the future.</p>
<p>©2016 WatchIot</p>
</td>
</tr>
</table>
</td></tr>
</table>
</body>
</html>