So I've just been testing some code in yahoo mail and it appears to be stripping display:none; I had a look at some working tests I sent yesterday and they're broken now too.

Not fun.

Not too big of an issue, you can still use the Gmail trick max-height:0px;overflow:hidden; on a block element to hide things.

The yahoo mail app still apears to be respecting display:none; and I updated that a few days ago, but I wouldn't be supprised if they dropped support on the next update.

Let me know if you spot anyother changes.