Background
Tailwind is set-up using the cssbundling-rails gem which bundles all CSS into a single file: app/assets/builds/application.tailwind.css.
In dev env, emails are correctly rendered as premailer-rails turns the (tailwind) CSS classes into inline styles. I use mailcatcher to preview emails. This works because of the reference to the stylesheet in layouts/mailer.html.erb:
<%= stylesheet_link_tag "application" %>
Problem
In production env (heroku), emails are not rendered with CSS. The CSS classess have been removed without being replaced by inline-styles.
Any ideas?
Many thanks in advance.