Email Template trick: max-width with outlook

max_width_email.html

<!--[if mso]>
 <center>
 <table><tr><td width="580">
<![endif]-->
 <div style="max-width:580px; margin:0 auto;">
 
 <p>This text will be centered and constrained to 580 pixels even on Outlook which does not support max-width CSS</p>
 
 </div>
<!--[if mso]>
 </td></tr></table>
 </center>
<![endif]-->