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 sitting in someone else's cloud. Not a line item on somebody's P&L.
The words you write, and the people you reach, answer to you. Not to a corporation.
Software was meant to empower you. But somewhere along the way, we ended up with the reverse.
So we are building email that no government and no mega-corporation can ever 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.
Free native apps to download
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, with 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, all handled for you.
Cloud MX pricing, 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.