Custom Mail

01. Project Overview

Self-hosted web mail workspace written in Rust (workers-rs): session login, Markdown compose with email-safe preview, attachments, send history in KV, and drop-in ESP / theme / layout plugins — without running a mail server.

02. Problem

Why build this?

Teams needed a private compose UI they could brand and host on their own Cloudflare account — not another shared SaaS mailbox, and not a VPS mail stack to babysit.

03. Solution

How was it solved?

Shipped Custom Mail as a Workers + KV product with JSON-driven branding, pluggable providers (Brevo, Resend, SendGrid, …), Docker / GHCR images, docs, and a ClawHub skill for agent installs.

04. Architecture

System architecture

05. Key Features

Core capabilities

• Password-protected compose console on Cloudflare Workers
• CommonMark + GFM body with email-safe HTML preview
• Attachments (multi-file caps) and last-N send history in KV
• Brandable config: name, domain, colors, logo, footer, copy
• Pluggable ESP / theme / layout / logo catalogs
• Docker Hub + GHCR images and ClawHub skill install path

06. My Role

What did I specifically do?

• Owned product architecture from Workers runtime through ESP plugins.
• Implemented Rust/wasm mail console, Markdown preview, and KV history.
• Published Docker / GHCR images, docs site, and ClawHub packaging.

07. Tech Stack

What technologies power it?

• Rust (workers-rs)
• Cloudflare Workers
• KV
• Brevo / Resend / SendGrid
• Docker
• OpenClaw / ClawHub

08. Metrics

What results can we show?

09. Deployment

How do you run it?

Deploy on Cloudflare Workers with secrets + KV, or run locally via Docker / wrangler; configure branding and ESP in config/mail.json.

1. Clone InnoNestX/Custom-Mail and copy .dev.vars.example.
2. Set ADMIN_PASSWORD and provider API key, then npm run dev or docker run.
3. Point wrangler routes + mail.json host at your domain and deploy.
4. Optional: clawhub install custom-mail for the OpenClaw skill path.

10. GitHub

11. Live Demo

12. Tradeoffs

• Self-hosted Workers + KV over a SaaS webmail — credentials and branding stay on your account.
• Outbound compose console instead of full IMAP inbox — focused on send workflows teams actually run.
• Pluggable ESP adapters instead of one locked provider — swap Brevo / Resend / SendGrid via config.

13. What shipped

• Private compose UI with session login on Cloudflare Workers
• Markdown preview + attachments + KV send history
• Install surfaces: Workers deploy, Docker / GHCR, and ClawHub

14. Inspectable proof

15. Links