Proton Mail vs Mailbox.org
Both are alternatives to Gmail. Here's how they stack up — verified facts, no spin.
Also searched as Mailbox.org vs Proton Mail — same comparison, one verdict.
Proton Mail is open source (GPL-3.0 (apps)) and Mailbox.org is not (Proprietary) — so the real question is whether you want to own the email & secure mail stack or rent it.
Proton Mail
TOP PICKEnd-to-end encrypted, open-source, Swiss — the privacy default.
Proton Mail is the most mature encrypted email provider, with over 100 million users and open-source apps on every platform. Mail is end-to-end and zero-access encrypted, it's based in Switzerland under strong privacy law, and it supports OpenPGP so mail with other PGP users is automatically end-to-end encrypted. It has grown into a genuine Gmail replacement with Calendar, Drive, Pass, and VPN in one account, plus a functional free tier.
Mailbox.org
German privacy-focused mail with a full office suite — standards-based.
Mailbox.org is a German, privacy-respecting email host for people who want a professional, standards-based inbox (IMAP/SMTP, custom domains) with an integrated office suite and calendar, powered by 100% renewable energy. It offers PGP encryption and an encrypted-mailbox option, but it's a commercial, closed service rather than open-source — the honest “privacy-friendly and full-featured, without encryption-first constraints” pick.
Side by side
6 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Proton Mail | Mailbox.org | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 84 | 50 |
| Open source | Yes | No |
| Self-hostable | No | No |
| Local-first data | No | No |
| License | GPL-3.0 (apps) | Proprietary |
| Pricing | Free (1GB); paid Mail Plus ~$4/mo; bundled Proton Unlimited adds Drive, VPN, and Pass | From about €1/month (Light) up to office and business tiers; custom domains supported |
Proton Mail is Macrostack's recommended Gmail alternative, so it's our pick here.
Weighing both against staying on Gmail? Is Gmail free? What it actually costs →
Proton Mail
Strengths
- +End-to-end, zero-access encryption with OpenPGP support
- +Open-source apps, independently audited, Swiss jurisdiction
- +Free tier; custom domains on paid plans
- +Part of a full privacy suite (Calendar, Drive, VPN, Pass)
Trade-offs
- −Encryption to non-Proton, non-PGP contacts needs password-protected mode
- −A hosted service you don't self-host
- −Free-tier storage is modest (1GB)
Mailbox.org
Strengths
- +Cheap, standards-based (IMAP/SMTP), custom domains
- +German/EU privacy law; PGP support and an encrypted-mailbox option
- +Integrated calendar, contacts, and office suite
Trade-offs
- −Closed-source, commercial service
- −Not end-to-end by default (PGP is opt-in)
- −Interface is more utilitarian than polished
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Proton Mail
if you want the source and the option to fork it, and end-to-end, zero-access encryption with OpenPGP support.
Choose Mailbox.org
if cheap, standards-based (IMAP/SMTP), custom domains.
Neither, yet
if both carry a real cost you should weigh first — encryption to non-Proton, non-PGP contacts needs password-protected mode, and closed-source, commercial service. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
Proton Mail vs Mailbox.org — common questions
Is Proton Mail a better fit than Mailbox.org for email & secure mail?
It depends on what you are optimising for, and the honest split is this: Proton Mail scores 84 to Mailbox.org's 50 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. Mailbox.org earns its place on a different axis — cheap, standards-based (IMAP/SMTP), custom domains. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Neither of these is local-first by default, so plan the exit at the point you adopt rather than later. Export what matters on a schedule instead of trusting you can retrieve it on demand — that is the most common way a email & secure mail migration turns into a project instead of an afternoon.
Is Proton Mail free?
Proton Mail: Free (1GB); paid Mail Plus ~$4/mo; bundled Proton Unlimited adds Drive, VPN, and Pass. The other side of this comparison, Mailbox.org, is priced as From about €1/month (Light) up to office and business tiers; custom domains supported. "Free" here means no licence fee — if you self-host it you still pay for the server, and the running cost row above is our honest estimate of that.
Are Proton Mail and Mailbox.org both alternatives to Gmail?
Yes — both appear in our Gmail comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off Gmail and now choosing between the two replacements, which is a narrower and much easier question.
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Facts verified 2026-07-14. Licenses and pricing change — spotted something out of date? That's a correction we want.