Branded HTML mailpieces

An HTML mailpiece body can now be branded. Set your own colours, wrap content in a hero card, and add a call-to-action button: the branded "envelope" look, delivered to the inbox.

What's new

  • Inline styles: style="…" is now honoured for a validated set of CSS properties (colour, spacing, border, size, text, and layout). Every value is checked, and no url()-valued property is allowed, so a style can never load a remote asset or become a tracking pixel.
  • kp-* blocks: a small vocabulary of ready-made classes: a soft kp-panel, a full-bleed kp-panel--brand hero, a kp-button CTA, and kp-lede / kp-muted text styles. Unlike a raw colour, these carry a light and dark variant, so they stay legible whichever theme the recipient uses.
  • tel: links are now supported for contact footers.
  • The portal composer builds all of this for you, with a live preview.

Everything is still sanitised on write: scripts, <style> blocks, external assets, url(), and layout-escape tricks are stripped, every time.

See HTML and CSS for the full reference.

Back to every dated change.