I've called background images in my html newsletter and these images are not showing up in my outlook and in gmail also:
Code:
<td style="font-family: calibri;font-size:16px;color:#000;font-weight:bold;padding-left:4px;border-top:1px solid #039AE0;border-bottom:1px solid #039AE0;border-left:1px solid #039AE0;border-right:1px solid #039AE0;border-radius:25px;background: url('http://mysite/newsletter/images/truy.jpg') repeat-x;text-align:center;" height="40" >3900 AED</td>