Encryption19 of 27
Trust and audits4 of 26
Apps and access8 of 18
Mailbox2 of 13
Price10 of 16
encrypted email service · Posteo e.K.
Posteo
German paid mailbox for 1 euro a month, with optional encryption of stored mail, contacts and calendar.
In short
- One plan costs 1 euro a month and includes a 4 GB mailbox1.
- Crypto mail storage is switched on by you; Posteo says it can then no longer read stored mail4,8.
- Contacts and calendar can also be encrypted so Posteo cannot read them9.
- Posteo's latest transparency report lists 85 legal requests received in 20256.
- There is no free plan and no own-domain option5.
Posteo suits people who want a low-cost mailbox that opens in Thunderbird or Outlook over IMAP, with optional encryption of stored data1,2,4. Its transparency report is current, and it holds a German BSI certificate for secure mail transport6,7. The catch: encryption is opt-in, mail between Posteo users is not automatically end-to-end encrypted, and there are no native apps or custom domains3,4,5.
Best for: People who want a cheap mailbox that works in standard mail programs.
Where the points come from
Encryption 19 of 27 points
| Rule | What is published | Points |
|---|---|---|
| Stored mail the provider cannot read | YesWith crypto mail storage on, Posteo says stored mail is no longer readable by it; the key is protected by your password4,8. | 10 / 10 |
| Automatic end-to-end encryption between its own users | NoMail between Posteo users stays on its servers; end-to-end encryption is optional and needs S/MIME or OpenPGP keys set up by users4. | 0 / 8 |
| Encrypted mail to other providers | YesWebmail sends OpenPGP-encrypted mail through the Mailvelope browser extension; S/MIME is also supported2,4. | 6 / 6 |
| Encrypted contacts or calendar | YesOptional setting encrypts address book and calendar; Posteo says it cannot view the data9. | 3 / 3 |
Trust and audits 4 of 26 points
| Rule | What is published | Points |
|---|---|---|
| Independent audit since 2024 | Not publishedPosteo says Cure53 audited crypto mail storage, but gives no report, summary or date4,11. | 0 / 8 |
| Open-source apps | Not publishedPosteo says it uses open-source software, but names no licence or repository for its own apps2. | 0 / 6 |
| SOC 2 Type II or ISO 27001 | Not publishedNot published on the vendor's security page; it names only a BSI TR-03108 certificate7. | 0 / 4 |
| Transparency report | YesTransparency report has a 2025 section: 85 requests received6. | 4 / 4 |
| Security key for two-factor sign-in | Not publishedHelp page names YubiKey as an alternative to a TOTP app; FIDO2 or WebAuthn keys are not mentioned10,3. | 0 / 4 |
Apps and access 8 of 18 points
Mailbox 2 of 13 points
| Rule | What is published | Points |
|---|---|---|
| Your own domain | NoFAQ says own domains are not supported5. | 0 / 5 |
| Mail storage on the cheapest paid plan | 44 GB included in the 1 euro plan; can be raised to 75 GB2. | 2 / 5 |
| Export your whole mailbox | Not publishedNot published on the vendor's features page or FAQ; they describe only import into Posteo2,5. | 0 / 3 |
Price 10 of 16 points
The rule behind each line: how we score encrypted email services.
Plans and prices
As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.
| Plan | Price as listed | Per month | Notes |
|---|---|---|---|
| Posteo mailbox1 person | 1 euro/month1,2 | – | 4 GB, 3 aliases; extra storage costs 0.25 euro per GB a month |
Posteo shows its price in euros only; the build converts it to dollars1.
Strengths
- Costs 1 euro a month for 4 GB, with no tiers to compare1.
- Crypto mail storage covers existing and new mail, and Posteo says it cannot read it or switch the encryption off4,8.
- Address book and calendar can be encrypted so that Posteo cannot view them9.
- Works with standard mail programs over IMAP and POP32.
- Publishes a transparency report with a 2025 section giving request counts6.
Limits
- Posteo says it offers no free accounts5.
- Own domains are not supported5.
- Crypto mail storage is off until you turn it on, and a forgotten password means the archive is lost8.
- Mail between Posteo users is not end-to-end encrypted automatically; OpenPGP or S/MIME must be set up4.
- Only a web app is offered; no native desktop or mobile apps are listed2,3.
What Posteo e.K. says
Vendor claims. We show them, but they earn no points.
- Posteo says its product offering uses only open-source software and free protocols2.
Other encrypted email services
- 1
Proton MailPeople who want a free encrypted mailbox that grows into a paid one with custom domains and Outlook or Thunderbird access85/100$3.99/mocheapest paid plan - 2
Tuta MailPeople who want contacts and calendar encrypted too, and are fine using Tuta's own apps instead of a mail program73/100$3.36/mocheapest paid plan - 3
Forward EmailPeople with their own domain who want IMAP access and a low price56/100$3/mocheapest paid plan - 4
mailbox.orgPeople who want to read their mail in Thunderbird or Outlook and switch on encryption themselves49/100$1.12/mocheapest paid plan
Sources
- Posteo, Posteo. Accessed 8 Oct 2026.
- Features, Posteo. Accessed 8 Oct 2026.
- Feature table, Posteo. Accessed 8 Oct 2026.
- Encryption, Posteo. Accessed 8 Oct 2026.
- FAQ, Posteo. Accessed 8 Oct 2026.
- Transparency report, Posteo. Accessed 8 Oct 2026.
- Security, Posteo. Accessed 8 Oct 2026.
- How do I activate Posteo crypto mail storage?, Posteo. Accessed 8 Oct 2026.
- How does encryption of the address book and calendar work?, Posteo. Accessed 8 Oct 2026.
- What is two-factor authentication and how do I set it up, Posteo. Accessed 8 Oct 2026.
- New: Posteo S/MIME add-on available now, Posteo. Accessed 8 Oct 2026.
- Euro foreign exchange reference rates: US dollar, European Central Bank. Accessed 8 Oct 2026.
Website: posteo.de/en · Markdown version · We are not affiliated with Posteo e.K..