Gmail changes the height property (as inline style) to min-height. So it changes this:

<img src="example.jpg" width="60" height="60" style="max-width:100% !important; height: auto !important; display: block !important;">

To this:

<img src="example.jpg" width="60" height="60" style="max-width:100% !important; min-height: auto !important; display: block !important;">

I'm trying to use responsive images with flexible heights so trying to find a workaround for this. Any fixes or solutions you know of?