In a perfect world, email clients can render HTML as good as major browsers. Unfortunately, this is not the case. Email clients don't support modern HTML and CSS niceties and have a lot of quirks to be mindful of. Making sure an HTML email looks good in the most used email clients takes a lot of work. To make crafting HTML emails a lot more enjoyable, the folks at Mailjet created a solution called MJML, which stands for "Mailjet Markup Language." It's an easy-to-use abstraction layer over HTML. We have created a new package called spatie/mjml-php to easily convert MJML to HTML using PHP. If you're using Sidecar, you'll be happy to know that we've also created a package called spatie/mjml-sidecar, to convert MJML to HTML using Sidecar. In this blog post, I'd like to introduce the package to you.