All I can tell you is getting an email to render correctly in Outlook is a pain in the ass. It's engine barely supports HTML in my humble opinion.
Start reading
this stuff[
^].
When I did this, I had some HTML tables that didn't render properly. I fixed it by wrapping my HTML in the following template:
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /></head>
<body>
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr><td>
<table class="content" align="left" cellpadding="0" cellspacing="0" border="0">
<tr><td>
{Email body HTML goes here}
</td></tr>
</table>
</td></tr>
</table>
</body>
</html>
I MAKE NO GUARANTEES THAT THIS WILL WORK FOR YOU!