Posteo privacy rating

Summary

Posteo scores 62 out of 100 (grade C) on the email providers criteria. It meets 9 of 19 criteria: no trackers or telemetry, no ads or data sales, transparency report, TLS configuration, encrypted mailbox storage, open protocols, sign up without personal data, IMAP support and POP3 support. It partly meets independent audit, security headers, end-to-end encryption and SMTP submission. It does not meet open source, tells users about requests, custom domains, mail transport security, Sender Rewriting Scheme and ARC sealing. It is based in Germany: Fourteen Eyes member; EU member (GDPR). Automated tests: SSL Labs grade A+ and Mozilla HTTP Observatory grade B+.

Score 62 out of 100. How scoring works

Criteria

• ✖No

  Open source ×3Weight 3 of 3

  Is all the source code needed to run the product public?

  Closed source. The crypto mail storage plugin for Dovecot is published, but the rest of the service code is not.

  posteo.de

• ✔Yes

  No trackers or telemetry ×3Weight 3 of 3

  Are the website and apps free of third-party trackers, with any analytics anonymous and any telemetry off by default?

  The privacy policy states that the website and webmail have no tracking, no Google products and no third-party captchas.

  posteo.de

• ✔Yes

  No ads or data sales ×2Weight 2 of 3

  Is the product funded without advertising, ad targeting or selling user data?

  Funded by paid accounts. No ads and no advertising partners.

  posteo.de

• ◐Partial

  Independent audit ×2Weight 2 of 3

  Has an independent security or privacy audit been published within the last three years?

  Cure53 audited the crypto mail storage feature, but the report is not published.

  posteo.de

• ✔Yes

  Transparency report ×2Weight 2 of 3

  Does the provider regularly publish how many government and legal requests it receives and how it responds?

  Publishes yearly counts of authority requests by type, legality and outcome. The German version is the most current.

  posteo.de

• ✖No

  Tells users about requests ×1Weight 1 of 3

  Does the provider promise to tell users about requests for their data, unless a court forbids it?

  Posteo states that German law does not allow it to inform affected users.

  posteo.de

• ◐Partial

  End-to-end encryption ×3Weight 3 of 3

  Can mail be end-to-end encrypted so that the provider cannot read message contents?

  PGP, S/MIME and password-encrypted mail are built into the webmail, but must be set up by the user.

  posteo.de

• ✔Yes

  Encrypted mailbox storage ×3Weight 3 of 3

  Is stored mail encrypted with a key the provider does not hold?

  Optional crypto mail storage encrypts all stored mail with a key protected by the user's password. It is off by default.

  posteo.de

• ✔Yes

  Open protocols ×2Weight 2 of 3

  Can any standard app connect over IMAP, POP3, SMTP, CalDAV or CardDAV, without extra software?

  IMAP, POP3 and SMTP work with any client.

  posteo.de

• ✖No

  Custom domains ×1Weight 1 of 3

  Can mail be sent and received with your own domain?

  Posteo does not support custom domains.

  posteo.de

• ✔Yes

  Sign up without personal data ×2Weight 2 of 3

  Can an account be created without a phone number or another email address?

  No name, address, phone number or other email address is required to register.

  posteo.de

• ✖No

  Sender Rewriting Scheme ×1Weight 1 of 3

  Is the envelope sender rewritten with SRS when mail is forwarded, so forwarded mail keeps passing SPF?

  No published documentation on SRS for forwarded mail.

• ✖No

  ARC sealing ×1Weight 1 of 3

  Does the provider validate and add ARC (RFC 8617) signatures, so authentication results survive forwarding?

  No published documentation on ARC signing or validation.

Automated tests

• ✔Yes

  TLS configuration ×2Weight 2 of 3

  Does the website pass the Qualys SSL Labs test with a grade of A or better?

  Grade A+

  ssllabs.com

• ◐Partial

  Security headers ×1Weight 1 of 3

  Does the website pass the Mozilla HTTP Observatory test with a grade of A or better?

  Grade B+ (80/100+)

  developer.mozilla.org

• …Not tested yet

  Modern web standards ×1Weight 1 of 3

  Does the website score 90% or higher on the Internet.nl website test?

  Not tested yet.

• …Not tested yet

  Email security standards ×2Weight 2 of 3

  Does the mail domain score 90% or higher on the Internet.nl email test?

  Not tested yet.

• ✔Yes

  IMAP support ×2Weight 2 of 3

  Does the IMAP server accept connections over implicit TLS on port 993 and advertise IMAP4rev1 or IMAP4rev2 with IDLE push?

  posteo.de:993 (implicit TLS). IMAP4rev1 advertised with IDLE.

• ✔Yes

  POP3 support ×1Weight 1 of 3

  Does the POP3 server accept connections over implicit TLS on port 995 and answer CAPA with UIDL?

  posteo.de:995 (implicit TLS). CAPA: CAPA, TOP, UIDL, RESP-CODES, PIPELINING, AUTH-RESP-CODE, USER, SASL.

• ◐Partial

  SMTP submission ×2Weight 2 of 3

  Does mail submission work over implicit TLS on port 465 with SMTPUTF8, 8BITMIME, PIPELINING and AUTH?

  posteo.de:465 (implicit TLS). Missing: SMTPUTF8.

• ✖No

  Mail transport security ×3Weight 3 of 3

  Does the mail domain enforce encrypted, authenticated delivery with MTA-STS, DANE, DNSSEC, TLS-RPT and an enforced DMARC policy?

  Passes: SPF, MTA-STS enforce, TLS-RPT, DNSSEC, DANE all. Missing: DMARC none.

Email standards

• ✔Yes: Mail serversMXmx01.posteo.de, mx02.posteo.de, mx03.posteo.de, mx04.posteo.de
• ✔Yes: RFC 7208 sender policySPFpublished
• ✖No: RFC 7489. Quarantine or reject counts as enforcedDMARCp=none
• ✔Yes: RFC 8461 strict transport securityMTA-STSenforce
• ✔Yes: RFC 8460 TLS failure reportsTLS-RPTpublished
• ✔Yes: RFC 4033 signed DNSDNSSECsigned and validated
• ✔Yes: RFC 7672 TLSA records on MX hostsDANEall
• ✖No: Brand logo record (not scored)BIMInone
• ✔Yes: RFC 6186 and RFC 8314 service records (not scored)SRVclient autoconfiguration published

Capabilities are what each server advertises before login. How these tests work