Approach for preventing use of tailwind classes that aren't supported by email clients

[georgewitteman]

Goals

1. We would like to prevent the use of tailwind classes that aren't widely supported by email clients (e.g. flex)

Background

Previously this could be done by setting a static set of corePlugins in the tailwind config, but that option isn't available anymore in tailwindcss v4. It also doesn't seem like there's a way to do this with the tailwindcss eslint plugin.

Proposal

It would be great to have the ability to whitelist the built in tailwindcss plugins. A blacklist would also work so we could disable known unsafe classes.

Relevant discussions

• [v4] add support for disabling core plugins tailwindlabs/tailwindcss#16132
• [v4] How to disable container? tailwindlabs/tailwindcss#16323