Yes, it is feasible, and many email marketing companies do that. Whether or not it is a good strategy is another question, which I'm not competent to reply.
Sending image as THE email is typically through an html table: First slice the image into pieces. Then each piece will be referred to in a in the html as a hyperlink which refers to the image piecw which will be get from a remote image server when the client accepts to download image.
One thing that you should take care of to ensure correct rendering of images is that when you make a column on image, the area on the image below that should also have that column. The other is that the width normally should not exceed 700px.
The html table can be generated automatically in Photoshop (and perhaps other software). It is a point and click thing . You just need to use slice tool, and then right click on each slice and assign the appropriate url/mailto/etc. so no pain at all. Sorry have no access to PS to explain the process in details. See an example Photoshop generated html below:
</head>
<body bgcolor="#FFFFFF" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<!-- Save for Web Slices (Image-title-1) -->
<table id="Table_01" width="700" height="1043" border="0" cellpadding="0" cellspacing="0">
<tr>
<td colspan="5">
<a href="http://google.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_01.jpg" width="700" height="76" border="0" alt=""></a></td>
</tr>
<tr>
<td colspan="5">
<img src="http://fictitiousimageserver/Image-title-1_02.jpg" width="700" height="25" alt=""></td>
</tr>
<tr>
<td>
<a href="mailto:[email protected]" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_03.jpg" width="149" height="409" border="0" alt=""></a></td>
<td>
<a href="http://digg.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_04.jpg" width="132" height="409" border="0" alt=""></a></td>
<td>
<a href="http://facebook.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_05.jpg" width="132" height="409" border="0" alt=""></a></td>
<td>
<img src="http://fictitiousimageserver/Image-title-1_06.jpg" width="133" height="409" alt=""></td>
<td>
<a href="http://me.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_07.jpg" width="154" height="409" border="0" alt=""></a></td>
</tr>
<tr>
<td>
<a href="nimport.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_08.jpg" width="149" height="453" border="0" alt=""></a></td>
<td>
<a href="http://master.com" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_09.jpg" width="132" height="453" border="0" alt=""></a></td>
<td>
<a href="http://google.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_10.jpg" width="132" height="453" border="0" alt=""></a></td>
<td>
<img src="http://fictitiousimageserver/Image-title-1_11.jpg" width="133" height="453" alt=""></td>
<td>
<a href="http://google.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_12.jpg" width="154" height="453" border="0" alt=""></a></td>
</tr>
<tr>
<td>
<a href="http://mydomain.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_13.jpg" width="149" height="80" border="0" alt=""></a></td>
<td>
<a href="http://mydomain.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_14.jpg" width="132" height="80" border="0" alt=""></a></td>
<td>
<a href="http://mydomain.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_15.jpg" width="132" height="80" border="0" alt=""></a></td>
<td>
<a href="http://mydomain.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_16.jpg" width="133" height="80" border="0" alt=""></a></td>
<td>
<a href="http://mydomain.com/" target="_blank">
<img src="http://fictitiousimageserver/Image-title-1_17.jpg" width="154" height="80" border="0" alt=""></a></td>
</tr>
</table>
<!-- End Save for Web Slices -->
</body>
</html>