The engine of Vulos Mail

lilmail

A lightweight, database-free webmail client in a single Go binary.

lilmail connects to any IMAP/SMTP mailbox and ships as one self-contained Go binary — server-rendered HTML with every asset embedded. No build step, no CDN, no database to run. Drop the binary next to a config.toml and it runs comfortably on 64 MB of RAM.

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Everything in one binary

Self-hostable, open source, and built to run anywhere.

Single binary, no database

Templates and vendored JS embedded via embed.FS; durable state in an embedded bbolt file by default, with an optional Postgres backend for shared deploys.

IMAP & SMTP

Connect to any mailbox: browse folders, search, flag, and compose with attachments, rich text, and 30-second auto-saved drafts.

Clean /v1 JSON API

A REST surface (folders, messages, search, flags) that powers the Vulos Mail React client and Vulos Workspace — same engine, same session auth as the HTMX UI.

OAuth2 / OpenID Connect

Authorization-code flow with PKCE (S256), XOAUTH2 and OAUTHBEARER SASL, and automatic refresh-token handling. Password login still works.

Calendar, contacts & AI

Opt-in CalDAV calendar, CardDAV contacts, and an AI assistant for thread summaries, smart compose, and phishing detection — zero overhead when disabled.

Security-first

JWT sessions, AES-256-GCM encrypted credentials at rest, a strict Content-Security-Policy, a sandboxed email iframe, and a hand-written dark mode.

Quick start

Up and running in a couple of commands.

git clone https://github.com/vul-os/lilmail.git
cd lilmail

# Configure — copy the example and fill in your mail server + secrets
cp config.toml.example config.toml   # then edit

# Run
go run main.go            # or: make build && ./lilmail
# open http://localhost:3000

1
Install or buildGrab a release binary, or build from source with the Go toolchain.
2
ConfigureA single config file (or flags) — sensible, secure defaults out of the box.
3
Run & openOne process, no external services. Open it in your browser and you are done.

Part of Vulos

Vulos is an open, self-hostable web OS and app suite. lilmail runs perfectly standalone — and can be combined under one login alongside Vulos Mail, Talk, Meet, Office, and more by Vulos Workspace.

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