Inkletter

Write your emails like prose, send them like a pro.

Inkletter turns plain Markdown files into beautiful, responsive MJML and HTML email layouts, ready to be previewed, shared or sent to the world.

Why Inkletter?

Because writing HTML emails by hand is like ironing socks: pointless and painful.

With Inkletter, you write your content in Markdown (like a decent human being), and it becomes a gorgeous, mobile-friendly HTML email powered by MJML.

Features

• Markdown to MJML or to final responsive HTML, in one command
• Seven built-in themes, or your own theme in a small TOML file
• Live preview in your browser, with a device simulator (iPhone, iPad, desktop)
• Clean Python API if you'd rather script it
• Runs entirely on your machine, no account, no vendor lock-in

Installation

Python 3.10+ required.

pip install inkletter

Or for development:

git clone https://github.com/lpauloin/Inkletter.git
cd Inkletter
pip install -e .

Usage

Preview a Markdown file as a responsive email

inkletter preview newsletter.md

Opens a split view in your browser: your Markdown, the generated MJML, and the rendered email in a device simulator.

Convert to HTML

inkletter md2html newsletter.md -o newsletter.html --view

Writes the final email HTML, and opens it in your browser with --view.

Export the raw MJML

inkletter md2mjml newsletter.md -o newsletter.mjml

Without -o, the MJML is printed to stdout, ready to be piped anywhere.

Image layout

Layout is driven by plain CommonMark structure — no custom syntax, the same file stays clean in any Markdown editor (and reusable for other channels):

• A paragraph made only of images becomes a row of side-by-side columns (up to 4 on one row, more wrap into rows of 3):

  ![Left view](left.png) ![Right view](right.png)
  

• A paragraph starting (or ending) with a single image beside text becomes a media object — image next to its text, 30/70 by default. Put the image last to place it on the right:

  ![Portrait](jean.png) Jean joined the team this week.
  He will own the rendering platform.
  

On mobile both patterns stack, image on top. Ratios, spacing and behaviour are tuned in the [images] theme section below — including text_layout = "stacked" to disable media-object columns entirely.

Theming

Every command accepts --theme with a preset name or a theme file, and --no-theme for bare, unstyled MJML:

inkletter md2html newsletter.md --theme dark
inkletter md2html newsletter.md --theme mytheme.toml

Built-in presets

Here is each preset rendered on desktop and on a 375px mobile screen:

Write your own

A theme file is partial — set only what you want to change, everything else keeps the default look:

[layout]
width = "640px"

[text]
font_family = "Georgia, serif"

[links]
color = "#c0392b"
underline = false

Any unknown section or key fails loudly, with the list of valid ones.

From Python

Same defaults, same presets, plus optional named color palettes:

from inkletter.colors import Blue
from inkletter.md_to_html import parse_markdown_to_html
from inkletter.theme import Links, Text, Theme

theme = Theme(text=Text(font_family="Georgia, serif"), links=Links(color=Blue.DARK))
html = parse_markdown_to_html(markdown, theme=theme)

Samples

• sample.md — the Markdown source
• sample.html — the generated responsive email
• sample/themes/ — the same source rendered with every preset

Contributing

French or not, you are welcome to contribute. Fork it, branch it, test it, PR it — with love.

pip install -r requirements-test.txt
pytest

Every push and pull request runs through the GitHub Actions CI on Python 3.10 to 3.13.

License

MIT — but don't forget to say "merci" 😉

Made with ❤️ and markdown in France.