I think a good approach to this is to take an established spec like CSS 2, and take a reductive approach. Many of the reasons we have problems with email design centers not around a lack of consensus on what to include, but rather what to exclude in the name of security/experience.
For instance, i’ve yet to see a solid use case for interactivity in email beyond the basics and things like video. Hamburger menus and progressive disclosure are fun tech experiments but they come with usability and security issues so I suggest we selectively exclude this kind of thing.
The group now has a number of participants from across a spectrum of stakeholders – client, server and webmail developers, people who produce HTML mail, and people who read it. Many have introduced themselves on the mailing list, and I hope others will continue to do so.
What HTML (and beyond – SVG, script, etc) works in which clients?
How to generate HTML for email
Accessibility, Security, Internationalisation, …
How do we improve the situation
What clients are people using, anyway?
There is also quite a lot of work that has been done over the years. We’ll try to collect stuff in our Wiki, and hopefully get enough done to produce one or more “CG report”s, but a couple of starting points include:
This is a community initiative. This group was originally proposed on 2014-01-29 by Charles McCathie Nevile. The following people supported its creation: Charles McCathie Nevile, Olivier Thereaux, Stefan Mies, Felix Sasaki, Arthur Barstow, Andrew Herrington, Robin Berjon, Jenny Schmitz, David Randall, Rémi Parmentier, marie hanotte, Remi Grumeau. W3C’s hosting of this group does not imply endorsement of its activities.
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