In outlook.com with email as xxx@outlook.com (not with www@live.fr, i don't know why) all images are modified :

<img src="http://xxx.com/casque.png" width="245" height="155" alt="" border="0" style="display:block;margin:auto;"/>

to :

<div style="display: inline-block;"><button type="button" class="_at_6 o365button" aria-labelledby="_ariaId_621"><img src="http://xxx.com/casque.png" alt="" style="display:block; margin:auto" width="245" height="155" border="0"><span class="_fc_3 owaimg" style="display: none;"> </span><span class="_fc_4 o365buttonLabel" id="_ariaId_621" style="display: none;"></span></button></div>

with inline-block, i have blank space under picture. I have added css rule: button, td div {display:block!important;} to fix but have you an other solution ?
Thank's and sorry for my bad english ;)