Posteo

Overview

Posteo was founded in 2009 and is headquartered in Berlin, Germany. It is a privacy-focused encrypted email service provider with a strong commitment to environmental sustainability. Its core philosophy delivers secure, green, and anonymous email at a fair price — just €1/month, powered by 100% renewable energy.

Posteo's servers run on Greenpeace Energy Lab-certified renewable electricity, and all email data is encrypted at rest on the server — meaning even Posteo itself cannot read user emails. Users can register anonymously using cash or prepaid cards without providing any name, address, or identity information. As of 2026, Posteo serves over 100,000 privacy-sensitive users worldwide and is one of Germany's most acclaimed eco-friendly email services.

Key Strengths

• €1/Month Ultra-Low Price: A flat €1/month with no tiered plans and no hidden fees — all features (mailbox, calendar, encryption) included. Compared to mainstream privacy email (ProtonMail starts at €3.99/month), Posteo offers the best value in encrypted email. See email service comparison.
• 100% Green Energy: All servers run on renewable energy certified by the Greenpeace Energy Lab, and every email carries carbon footprint information for transparent environmental impact — exceptionally rare among email providers.
• Anonymous Registration & Payment: Cash-by-mail and prepaid cards — 2 anonymous payment methods — with no personal identification required to create an account. A critical feature for journalists, activists, and identity-sensitive users.
• Server-Side Encryption: Email data is encrypted at rest with AES-256 on the server; Posteo cannot decrypt mailbox content. Combined with TLS transport encryption, emails are protected both in transit and at rest.

Product Ecosystem

Posteo Webmail

A clean, efficient webmail interface with calendar, contact management, and email filtering rules. The minimalist design is responsive for mobile, though there is no dedicated iOS/Android app. Standard IMAP/SMTP support allows configuration in Thunderbird, Outlook, Apple Mail, and other clients.

Built-in Calendar & Contacts

Every account includes calendar and contact management supporting CalDAV/CardDAV protocols for two-way synchronization with mainstream calendar apps (Apple Calendar, Thunderbird Lightning, etc.). Calendar data also benefits from server-side encryption protection.

Aliases & Email Filtering

Each account supports up to 50 alias addresses (e.g., [email protected]) for shopping, social, and subscription purposes. All alias emails consolidate into the main inbox, with per-alias filtering rules for automatic categorization.

Limitations

• No Custom Domain Support: Users can only use @posteo.de addresses and cannot bind their own domain as a branded mailbox. For business or webmaster scenarios, consider Migadu or StartMail.
• Limited Storage: The 2 GB base storage can be tight for large attachments, and expansion incurs additional fees. Users with heavy archiving needs should periodically clean up.
• No Dedicated Mobile App: Only a web interface is available with no native iOS/Android app. While IMAP works with standard clients, the lack of push notifications and native experience is less friendly for mobile workers.
• No Free Tier: Posteo has no free plan — all features require payment. Casual or low-frequency users can consider GMX Free Email.

Use Cases

• Privacy-Sensitive Personal Communication (★★★★★): Journalists, lawyers, and activists benefit from zero-identity registration and server-side encryption. Combined with GDPR compliance checklist, users can build a compliant privacy communication system.
• Environmentally Conscious Users (★★★★★): 100% green energy operations with transparent carbon footprint — ideal for eco-conscious individuals and green organizations.
• Budget-Conscious Secure Email (★★★★): At just €1/month, Posteo is ideal for students and freelancers who need encrypted email on a tight budget.
• Business Branded Email (★): No custom domain support makes it unsuitable for business use. Evaluate Migadu or Google Workspace.

Pricing

All prices include German VAT. No long-term contracts; pay monthly or annually with a 10% annual discount. Pricing sourced from Posteo's official website.

FAQ

• What's the difference between Posteo and ProtonMail? Posteo (€1/month) is cheaper with server-side encryption, while ProtonMail supports custom domains and end-to-end encryption. Posteo suits personal users on a budget who don't need custom domains. See email service comparison.

• Can Posteo really not read my emails? Yes. Email data is encrypted at rest on the server, and decryption depends on your password. Posteo has no decryption capability and cannot provide plaintext content even when legally required. In-transit encryption depends on whether the sender also uses TLS; see email service provider comparison for privacy-focused options.

• How do I pay for Posteo anonymously? You can mail cash (euro notes) to Posteo's Berlin address, or purchase a prepaid card within Germany. No name, address, or bank information is required — just include your Posteo username in the correspondence; see email service provider comparison.

• Can Posteo be used to register social media accounts? Yes. The @posteo.de domain is not blacklisted by major social platforms and can normally be used for registration, though some strict verification platforms may be cautious with privacy-focused email providers; see the business email service guide.

• How do Posteo aliases work? You can create up to 50 alias addresses in settings. All alias emails automatically consolidate into your main inbox, and you can set per-alias filtering rules for easy mail sorting; see the SPF/DKIM/DMARC setup guide.