Posteo vs Mailbox.org
Posteo (Posteo e.K., Berlin) is a single-purpose mailbox for 1 EUR a month with email, contacts, calendar and anonymous payment. mailbox.org (Heinlein Hosting GmbH, Berlin) starts at the same price but adds custom domains, Drive, Office and video meetings in higher plans. Posteo wins on anonymity and simplicity, mailbox.org on features.
Choose Posteo if
a plain, ad-free mailbox for 1 EUR a month, signing up without personal details and paying anonymously, including by cash, with no own-domain support.
Read the Posteo reviewChoose Mailbox.org if
your own domain name, family accounts, shared storage, an office suite and video meetings from a Berlin provider with ISO 27001 and BSI C5 certification.
Read the Mailbox.org reviewPosteo and Mailbox.org side by side
| Posteo | Mailbox.org | |
|---|---|---|
| Company | Posteo e.K. | Heinlein Hosting GmbH |
| Headquarters | Berlin, Germany | Berlin, Germany |
| Founded | 2009 | 2014 |
| Jurisdiction | EU (Germany) | EU (Germany) |
| Where the data sits | Germany (100% green energy) | Germany (green energy) |
| Pricing | €1/month flat rate | From about €1/month (Light) to €9/month (Business) |
| Entry-level list price (vendor site, checked 20 October 2026) | 1 EUR/month for 4 GB (extendable to 75 GB at 0.25 EUR per GB), 3 aliases included | Light 1 EUR/month (annual payment only), Standard 4 EUR monthly or 3 EUR with annual payment, Premium 12 EUR monthly or 9 EUR annually; private prices include VAT, 30-day free trial |
| Free tier or trial | No free tier; anonymous payment accepted | 30-day trial |
| Source code | Closed source | Closed source |
| Usually replaces | Gmail, Outlook | Gmail, Outlook, Google Workspace |
| Position in our Email Providers guide | #17 of 18 | #2 of 18 |
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 Posteo and Mailbox.org differ
Across the five points below, Posteo has the edge on 1 point, Mailbox.org on 2 points and 2 are 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.
Signing up and paying
Posteo's signup asks for no personal details, and its code system lets users pay by bank transfer or cash without linking payment to the account. mailbox.org takes the usual route of a contract and payment details per account. For anyone who wants as little personal data on file as possible, Posteo goes further.
Edge: Posteo
Own domain names
mailbox.org allows custom domains in its Standard and Premium plans, with 50 or 250 aliases on those domains and even a catch-all. Posteo's FAQ answers a flat no to own domains, because registered domains would force it to store customer data. If you run a business or a family domain, only mailbox.org fits.
Edge: Mailbox.org
Entry price and storage
Posteo costs 1 EUR a month for 4 GB, extendable to 75 GB at 0.25 EUR per extra gigabyte, with 3 aliases included. mailbox.org Light is also 1 EUR a month on annual payment, with 2 GB and 3 aliases; its Standard plan is 4 EUR monthly or 3 EUR with annual payment, for 20 GB. Posteo gives more storage at the lowest price, mailbox.org has more tiers.
No clear winner on this point.
Beyond email
Posteo offers email, address book, calendar and notes, and says its offering uses open-source software. mailbox.org adds 10 GB of Drive, Office and Meet in Standard, rising to 100 GB in Premium, plus family accounts for up to 10 people. Posteo has none of those modules, so mailbox.org is the one to compare with Google Workspace.
Edge: Mailbox.org
Hosting and certification
Posteo says all its servers and stored data are in Germany and runs on green energy from Green Planet Energy. mailbox.org states its servers are in Berlin and that it is ISO 27001 and BSI C5 certified. Posteo lists no such certificates on the pages we read, so on audits mailbox.org shows more, while both keep data in Germany.
No clear winner on this point.
When neither Posteo nor Mailbox.org fits
If you want end-to-end encrypted mail from outside Germany, look at Tuta or Proton Mail, which are also in the email-providers category on the site.
Posteo vs Mailbox.org: questions
No. Posteo's FAQ says own domains are not compatible with its privacy model, since they would require storing customer data. It offers other Posteo domains such as posteo.net and posteo.de instead.
On its prices page on 20 October 2026, Light was 1 EUR a month on annual payment, Standard 4 EUR monthly or 3 EUR on annual payment, and Premium 12 EUR monthly or 9 EUR annually. Private prices include VAT.
Neither lists a free plan. Posteo costs 1 EUR a month, and mailbox.org offers a free 30-day trial before its paid plans start.
Posteo says all its servers and data are in Germany. mailbox.org says its servers are located exclusively in Germany, in Berlin.
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.
- Posteo features page: 1 EUR/month price, 4 GB storage, aliases, feature set (checked 20 October 2026)
- Posteo FAQ: No support for own domains and the reason given (checked 20 October 2026)
- Posteo legal notice: Posteo e.K., Berlin, Handelsregister Berlin-Charlottenburg HRA 47592 B (checked 20 October 2026)
- mailbox.org prices page: Plan prices, storage, aliases, custom domains, family accounts (checked 20 October 2026)
- mailbox.org legal notice: Heinlein Hosting GmbH, Berlin, HRB 220010 B (checked 20 October 2026)
- mailbox.org security page: Servers in Berlin, ISO 27001 and BSI C5 (checked 20 October 2026)