Try placing your your class into the TD that holds it:
<td style="text-align: center;" class="bullet">
<img height="40" src="http://image.email.beachbody.com/lib/fe9912747462077d77/m/18/4d603cbc-ee2f-4b01-99fc-abbe6829d8ff.png" style="padding: 10px; text-align: left; height: 40px; width: 40px; border: 0px;" width="40">
or try to add display: block in the image's inline CSS
We are having similar issue. I have tried removing the VML codes and the image loads properly. I suspect this is due to the VML codes or a bug on Windows 10 Mail? Can anyone please help if you have encountered the similar issue? Thanks!