We are using mso-hide:all for show/hide some block for mobile block. Recently in one of email we have noticed that show/hide is not working for outlook app.
This was never picked up in litmus test too.
Does mso-hide not supported in outlook app?
<!----Normal block->
<!--[if !mso]><!-->
<div style="display:none; max-height:0px; mso-hide:all; overflow:hidden; visibility:hidden;">

<!-- <![endif]-->