Team email you actually own.
Open-source, offline-first apps for desktop, iOS and Android, free forever. Bring your own domain with Cloud MX.
Email you actually own.
Your messages are yours.
Not a hyperscaler's asset. Not data in someone else's cloud. Not a income line on a p&l.
The words you write — and the people you reach — answer to you, not to a corporation.
Software should empower humans, never restrict. Yet we find us in the reverse situation.
We are building an email platform that no government or mega-corporation can take away from you.
inbox2 is collaborative, domain-based email. All mail for your domain lands in one shared pool; everyone defines their own filtered views over it and routes patterns to people, AI agents, or webhooks.
The clients are open-source and free. Your inbox syncs into a local file on your own device — not a server you rent.
All your domain's mail in one pool. Everyone gets their own lens over it. No forwards, no shared-mailbox hacks.
The unified inbox, for your whole team.
One core. Every device. All free.
The native apps share one Rust engine and the same local data — read from SQLite, write through the core. No account required to start.
What runs on your device, for free:
The shared domain inbox, with each member’s own saved filtered views.
Get inbox2.
inbox2 is a free, open-source desktop client that connects all your personal email accounts into one unified inbox. No ads, no cloud, no lock-in.
And a cloud-hosted MX for your domain and team — free to start, easy to scale across many domains and collaborators.
Both are built with agentic UI in mind: point your agent straight at your mail — no finicky cloud vendors in between.
Download
The desktop and mobile apps are open-source and completely free — with or without a Cloud MX subscription. Connect Gmail, Microsoft or IMAP and use inbox2 for nothing at all.
Cloud MX
Point your domain's MX at inbox2 and every address becomes a shared team pool — inbound receiving, signed outbound, deliverability and spam handled for you.
Cloud MX pricing — the apps stay free
- 1 connected domain
- Just you — solo owner
- Inbound MX + signed outbound
- DKIM / SPF / MTA-STS handled
- Attachments up to 20 MB
- All native apps included
- 2 connected domains
- Owner + 2 collaborators
- Everything in Free, plus —
- Spam filter included
- AI auto-triage (Spaces)
- Attachments up to 100 MB
- Unlimited domains
- Unlimited collaborators
- Everything in Startup, plus —
- Spam filter on every domain
- AI auto-triage on all pools
- Attachments up to 100 MB
Team email you actually own.
Open-source, offline-first apps for every device — free. Host your domain with Cloud MX when you’re ready.