Update: Looks like Gmail reverted this change the following day.
As of today Gmail strips all attribute selectors (h/t Mark Robbins) as well as the :hover and :checked pseudo-class and that means no more interactivity in the Gmail inbox.
We had almost a two year run with this trick and it seems Gmail finally put the kibosh on it. AOL, Yahoo! Mail and to a lesser extent Outlook.com still support interactive email though.
To recap, Gmail Webmail has always stripped class and id attributes in email but allowed other attributes such as the “lang” attribute. With some attribute selector tricks we were able to make elements interactive within Gmail.
background-color: green !important;
<div lang="x-divbox">Divbox Content</div>
Well that is no more as of today. That means rollover images and interactive carousels no longer enjoy their independence within the Gmail inbox.
Happy fourth weekend everyone!