Use the HTML block in the drag-and-drop editor

The HTML block lets you insert a custom HTML fragment into the drag-and-drop editor when standard blocks are not enough.

Enable the HTML block

Go to Settings > Signature > Advanced and enable the Enable the HTML block option.

Open the Template tab, then click Edit to open the drag-and-drop editor.

In the left palette, add the HTML block.

When you select the block, the HTML code field appears in the right panel.

In the canvas, the block shows an <html> placeholder.
This is expected: the editor does not try to render arbitrary HTML directly inside the canvas.
In the final signature, the HTML fragment is rendered correctly.

The HTML is sanitized during preview and save.
Email-friendly structures remain allowed, including tables, text blocks, links, and images.
Sensitive tags such as script, iframe, and form are removed.
Links are limited to http, https, mailto, and tel.
Existing Twig tokens are preserved so signature variables continue to work.

To add a very specific layout fragment that is not available through the standard blocks.
To preserve an email rendering based on HTML already validated by your teams.
To answer an advanced need without misusing the other editor blocks.

Important: disabling the option removes the block from the palette, but HTML blocks already added to templates keep working.

Good to know: the placeholder in the editor does not mean the content is lost. It is only a visual hint while editing.

Keep in mind: the HTML block is mainly useful for advanced needs. For simple content, native blocks remain easier to maintain.