At first we should say that Microsoft word uses VML (Vector Markup Language) to produce vector graphics. This language allows including different figures, shapes and images in Microsoft Word. The most important thing for us is that VML supports image absolute positioning and z-indexes.

Here is the simplest code to insert a background image (for table td) into an HTML email for MS Outlook:

//-------------------------------------------------------------Start VML Code-------------------------------------------------------------//
<td>
       <!--[if gte mso 9]>
<v:image xmlns:v="urn:schemas-microsoft-com:vml" id="theImageTop" style='behavior: url(#default#VML); display:inline-block; position:absolute; height:131px; width:813px; top:0; left:0; right:0; bottom:0; border:0; z-index:1;' src="http://www.mindstick.com/newsletter/headerimg.png"/>
<v:shape xmlns:v="urn:schemas-microsoft-com:vml" id="theTextTop" style='behavior: url(#default#VML); position:absolute; display:inline-block; height:131px; width:700px; border:0; z-index:2;'> 
<![endif]-->
      <p> Your text here which you want to show on backgroung image. You can use here html tag too</p>
<!--[if gte mso 9]>
</v:shape>
<![endif]-->
</td>
//----------------------------------------------------------------End VML Code-----------------------------------------------------------//

The first set of previews demonstrated that the background image indeed displayed for Outlook 2007 and Outlook 2010. However, two problems were evident within these clients. First of all, the text within the hack was completely un-styled, even with the inline styles present. Secondly, the image displayed shifted out of the table cell, a few pixels downward and right.

Here some attributes like top, height, width, position and style etc having some values it is define according to my requirement, and you can change these values according to your code.