Hi.
Attribute selector fix for yahoo can be trimmed back to just body element:
body[yahoo] .hidemob1 {display:none!important;}

Now using this:
body .hidemob1 { display:none!important; }
As long as you reference your parent wrapper (ie:body) Yahoo doesnt fire the media queries in webmail.

Anyone had any issues with trimming this atribute selector off to just body element?