The E-Mail builder is accessible once you have saved your E-Mail. If you are using the builder, it will override your HTML content field, you will still need to set the text fallback content.
You should first choose your E-Mail template, &shift comes with 3 built-in templates.
We also have the possibility to create custom templates for your company.
Using the E-Mail builder is quite intuitive, you can easily add blocks in your E-Mail, define the content structued in the blocks and their styling.
Once finished, you can save your E-Mail and go back to the Mail E-Mail edition.