About Coldletter

We think email deserves craft.

Coldletter began with a folder of MJML hacks and a conviction that product email should be designed, versioned, and automated like real software — then handed to the provider you already trust. We build the design and automation layer so design owns the look, engineering owns one API call, and nothing breaks on send.

What we believe

Principles we build on.

Tonal depth, no lines

Boundaries come from warm tonal shifts — paper, sand, white — never borders. The interface reads like layered paper stock.

The power gap

A dramatic jump from oversized display type to calm body copy. Hierarchy comes from scale, not decoration.

One laser

A single coral accent, used once per view on the one thing that matters most. Restraint is what makes it read as premium.

By the numbers

Built for teams who ship.

±0.
Email tables you hand-code. Coldletter renders responsive, dark-mode-safe HTML for you.
6+
Provider backends supported — switch routes without touching a template.
99.9%
Render uptime, with idempotent sends and automatic retries.

Start today

Precision and craft for every email you send.

Connect your provider, import a template, and ship your first automated send before lunch.