Resend supports Tailwind CSS

Resend is an email API for developers. It handles transactional and marketing email at scale, with SDKs for most languages so sending fits inside the codebase rather than alongside it. Templates are built with react-email (an open source component library) instead of nested <table> HTML, and webhooks deliver real-time events back to your server every time a message is delivered, opened, bounces, or has a link clicked.

Resend treats email as infrastructure, on the same shelf as water, energy, and transportation (the kind of thing you don't think about until it's not there). That framing sets a different bar for uptime, deliverability, and the surface developers actually touch. Documentation isn't auxiliary to the product, it's part of it: the first thing you read when you integrate, and the thing you keep coming back to as you go deeper.