CSS Circle // Border Radius

<table cellpadding="0" cellspacing="0" border="0">
  <tr>
    <td align="left" valign="top" style="background-color:#FF0004;"><img src="http://placehold.it/100x100" alt="" width="100" height="100" border="0" style="display:block; border-radius:50%;" /></td>
  </tr>
</table>