Posteo

Posteo is a Berlin-based email, calendar and address-book provider powered entirely by renewable energy, built for people who want privacy and climate responsibility baked into the same service. There are no ads, no tracking, no cross-selling, and the provider has become a reference for what a quiet, ethical inbox can look like at one euro per month.

Technically, Posteo ships the full crypto stack: OpenPGP and S/MIME directly in webmail, mandatory TLS with DANE for secure routing, certificate pinning, and a one-click "crypto mail storage" option that encrypts the entire mailbox at rest. Calendars, contacts and notes can be encrypted too, so metadata is not quietly left in the clear the way it is with most providers.

Key benefits:

• Anonymous signup requires no personal data and decouples payment from account identity
• 4 GB storage with affordable upgrades and two included alias addresses
• Two-factor authentication via TOTP hardens every login
• Green energy sourced entirely from Green Planet Energy powers the whole operation
• Annual transparency reports document every government access request received

Posteo operates from Germany with servers in high-security German data centres, governed by strict federal data-protection law and the GDPR. The service holds BSI TR-03108 v2 certification for secure email transport (one of the more rigorous German trust seals) and publishes regular transparency numbers.

The result is a mailbox that quietly combines sovereignty, sustainability and serious cryptography without asking you to become a security expert to benefit from any of it.