Proton Mail vs Mailbox.org
Proton Mail and mailbox.org are both European paid-first mailboxes, and they differ in approach: Proton encrypts end to end by default and keeps to its own apps and Bridge, while mailbox.org is a German, ad-free, standards-based mailbox with optional PGP and plain IMAP, CalDAV and CardDAV. Proton has a 1 GB free plan; mailbox.org starts at EUR 1 a month.
Choose Proton Mail if
you want a free plan, end-to-end encryption without setting anything up, and the wider Proton suite (VPN, Calendar, Pass, Drive) on one login.
Read the Proton Mail reviewChoose Mailbox.org if
you want a low entry price (EUR 1 a month), a German company with certified German data centres, standard IMAP, CalDAV and CardDAV access, and Drive, Meet and Office in the same account.
Read the Mailbox.org reviewProton Mail and Mailbox.org side by side
| Proton Mail | Mailbox.org | |
|---|---|---|
| Company | Proton AG | Heinlein Support GmbH |
| Headquarters | Geneva, Switzerland | Berlin, Germany |
| Founded | 2014 | 2014 |
| Jurisdiction | Switzerland (adequacy decision, outside the EEA) | EU (Germany) |
| Where the data sits | Switzerland, Germany | Germany (green energy) |
| Pricing | Free (500MB) / from about €4.99/month | From about €1/month (Light) to €9/month (Business) |
| Entry-level list price (vendor site, checked 8 October 2026) | Free plan (1 GB); paid Mail Plus price not shown on the page when checked | Light EUR 1, Standard EUR 4, Premium EUR 12 per month (private plans, EUR; business plans per user); free 30-day trial |
| Free tier or trial | Free tier | 30-day trial |
| Certifications and checks | Independently audited, open source | Not stated in our data |
| Source code | Open source | Closed source |
| Usually replaces | Gmail, Outlook, Yahoo Mail | Gmail, Outlook, Google Workspace |
| Position in our Email Providers guide | #3 of 17 | #2 of 17 |
Both are listed in our European Email Providers guide. The table is built from the same directory data as those entries, except the list price, which is quoted from each vendor's own pricing page (see Sources below); how we check it is described in the editorial process.
Where Proton Mail and Mailbox.org differ
Across the five points below, Proton Mail has the edge on 2 points, Mailbox.org on 2 points and one is a tie. A count like that is a summary, not a verdict: the point that matters to you may be the one the other product wins.
Free plan
Proton Free gives 1 GB (expandable to 1.5 GB through its checklist) and 1 address. mailbox.org's pricing page lists Light, Standard and Premium and mentions a free 30-day trial, with no permanent free plan shown.
Edge: Proton Mail
Paid plans and entry price
mailbox.org lists Light at EUR 1 a month (2 GB mail), Standard at EUR 4 (20 GB mail plus 10 GB Drive) and Premium at EUR 12 (50 GB mail plus 100 GB Drive), with custom domains on Standard and Premium. Proton lists Mail Plus (15 GB, 10 encrypted addresses, 1 custom domain) and Proton Unlimited (500 GB, 3 custom domains), but the amounts did not render when checked, so the two cannot be compared on price here.
No clear winner on this point.
Encryption
Proton says its encryption happens in the background so anyone can use encrypted email. mailbox.org lists end-to-end encryption with PGP and S/MIME in its webmail plus TLS in transit, which you set up yourself, and says data is encrypted during storage and transmission. Proton asks less of you.
Edge: Proton Mail
Jurisdiction and certification
Proton says it is incorporated and headquartered in Switzerland and that its services are open source and independently audited. mailbox.org says its data is stored in certified German data centres and lists ISO 27001, BSI C5 attestation and 100 per cent renewable energy. mailbox.org gives the more checkable certification list; Proton gives the stronger open-source claim.
Edge: Mailbox.org
Standard protocols and the rest of the suite
mailbox.org lists IMAP, POP3 and SMTP for existing mail clients, CalDAV and CardDAV, aliases and disposable addresses, and an ad-free service with spam and virus filtering. Proton lists Bridge as a desktop add-on for mail apps and bundles VPN, Calendar and Pass in Proton Unlimited. For plain standards-based access without an extra app, mailbox.org is the simpler fit.
Edge: Mailbox.org
When neither Proton Mail nor Mailbox.org fits
If you want another encrypted mailbox with its own apps, compare Tuta, which is covered in our Proton Mail vs Tuta page. We did not verify its details for this page.
Proton Mail vs Mailbox.org: questions
Proton has one: Proton Free gives 1 GB (expandable to 1.5 GB) and 1 address. mailbox.org's pricing page lists three paid plans from EUR 1 a month and a free 30-day trial, and no permanent free plan.
It lists end-to-end encryption with PGP and S/MIME in its webmail, and TLS during transmission. You use it by setting it up, unlike Proton, which describes its encryption as happening automatically in the background.
mailbox.org says data is stored in certified German data centres. Proton says it is incorporated and headquartered in Switzerland; the pages checked did not name its data centre locations.
Both support it on paid plans. mailbox.org offers custom domains on Standard and Premium; Proton Mail Plus supports 1 custom domain and Proton Unlimited 3.
Sources
Facts, prices and plan details on this page were checked on the vendors' own websites on . Prices and plans change; the vendor's current page is authoritative.
- Proton Mail pricing: Proton Free, Mail Plus, Proton Unlimited storage, addresses and custom domains; prices not rendered (checked 8 October 2026)
- Proton Mail home page: Encryption in the background, open source and audited, Swiss base, Bridge, apps (checked 8 October 2026)
- mailbox.org home page: Plan prices and storage, German data centres, ISO 27001, BSI C5, renewable energy, 30-day trial (checked 8 October 2026)
- mailbox.org mail product page: PGP and S/MIME, ad-free, IMAP, POP3, SMTP, CalDAV, CardDAV, custom domains on Standard and Premium (checked 8 October 2026)