Postmark is hand-written HTML email. No framework, no build step, no mystery. There are twelve layouts and a handful of partials you paste together.

It uses tables, because in 2026 email still uses tables. The CSS is inlined and kept short so the weight stays under 60 KB including images.

I test every release in fourteen email clients, including the ones nobody uses, because that is where things break. Outlook on Windows is the hardest and it is supported.

Includes a Figma file so you can design the next issue before you touch code.

The details

Requirements

An email service that accepts custom HTML

Basic HTML knowledge to edit content

Figma only if you want to redesign

Version history

2.4.0

Fixed dark mode in Apple Mail — 2026-02-28

2.3.0

Added a plain-text template — 2025-09-30

2.0.0

Rebuilt on a cleaner partial system — 2025-01-12

1.0.0

First release — 2023-08-01