I've done a newsletter with mjml framework. I have to change the header image on mobile devices, but how? The framework is very helpful for doing bulletproof newletters, but doesn't support different images for different viewport.
This is the header code:
<table role="presentation" border="0" cellpadding="0" cellspacing="0" width="900" align="center" style="width:900px;">
<tr>
<td style="line-height:0px;font-size:0px;mso-line-height-rule:exactly;">
<![endif]-->
<div style="margin:0px auto;max-width:900px;background:#29c5f8;">
<table role="presentation" cellpadding="0" cellspacing="0" style="font-size:0px;width:100%;background:#29c5f8;" align="center" border="0">
<tbody>
<tr>
<td style="text-align:center;vertical-align:top;direction:ltr;font-size:0px;padding:20px 0px;padding-bottom:0px;padding-top:0px;">
<!--[if mso | IE]>
<table role="presentation" border="0" cellpadding="0" cellspacing="0"><tr><td style="vertical-align:top;width:900px;">
<![endif]-->
<div class="mj-column-per-100 outlook-group-fix" style="vertical-align:top;display:inline-block;direction:ltr;font-size:13px;text-align:left;width:100%;">
<table role="presentation" cellpadding="0" cellspacing="0" style="vertical-align:top;" width="100%" border="0">
<tbody>
<tr>
<td style="word-break:break-word;font-size:0px;padding:10px 25px;padding-top:0px;padding-bottom:0px;padding-right:0px;padding-left:0px;" align="center">
<table role="presentation" cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-spacing:0px;" align="center" border="0">
<tbody>
<tr>
<td style="width:900px;">
<a href="http://www.link.com" target="_blank">
<img alt="" title="" height="auto" src="http://www.link.com/img/img-desktop.png" style="border:none;border-radius:;display:block;outline:none;text-decoration:none;width:100%;height:auto;" width="900">
</a>
</td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]-->
</td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]-->
<!--[if mso | IE]>
Thanks for your support