Skiff

Overview

Skiff was founded in 2020 and is headquartered in San Francisco, California, USA. It is a privacy-focused, end-to-end encrypted email service platform offering encrypted mail (Skiff Mail), document collaboration (Skiff Pages), cloud storage (Skiff Drive), and calendar (Skiff Calendar) in a single integrated workspace. All data is protected by end-to-end encryption and zero-knowledge architecture.

Skiff employs decentralized storage — email content is fragmented, encrypted, and stored across the IPFS network, ensuring that even if servers are compromised, user data remains unreadable. In 2024, Notion acquired Skiff to integrate its encryption technology and collaboration capabilities into the Notion ecosystem. Prior to the acquisition, Skiff had accumulated over 500,000 registered users, making it one of the most notable privacy email platforms alongside ProtonMail.

Key Strengths

• True End-to-End Encryption: Emails are encrypted from sender to recipient — Skiff's servers cannot access plaintext content. Even under legal requests, Skiff cannot provide email content, offering privacy protection far beyond traditional email providers. See Encrypted Email Comparison.
• Zero-Knowledge Architecture: User passwords and encryption keys are generated and managed locally. Encryption keys are stored in fragmented form across the network, making them inaccessible to Skiff's servers. Even password resets cannot recover previously encrypted historical data.
• All-in-One Private Workspace: Email, documents, cloud storage, and calendar are unified under a single end-to-end encryption system. Users can handle encrypted communication, document collaboration, and file management on one platform without juggling multiple privacy tools.
• Decentralized Storage: Email and file data are fragmented, encrypted, and stored on the IPFS decentralized network, avoiding the single point of failure risk of traditional cloud storage while providing stronger data persistence and censorship resistance.
• Clean Modern UX: Skiff's UI design is inspired by Notion — clean, intuitive, and transparent about encryption operations, lowering the barrier to entry for privacy-focused tools.

Product Ecosystem

Skiff Mail

Skiff Mail is an end-to-end encrypted email client supporting custom domain email, email aliases, and PGP-compatible encryption. Users can send and receive encrypted emails via web or mobile apps. End-to-end encryption is automatically enabled between Skiff users; for non-Skiff recipients, emails can be shared via temporary passwords or secure links. Skiff Mail also supports auto-expiring messages, ideal for sharing sensitive information.

Skiff Pages

Skiff Pages is an end-to-end encrypted document collaboration tool comparable to Notion and Google Docs. It supports rich text editing, Markdown, tables, Kanban views, and real-time collaboration. All document content is encrypted client-side before syncing to Skiff servers; collaborators need the shared key to decrypt and view. Pages integrates seamlessly with Skiff Mail, allowing document links to be inserted directly into emails.

Skiff Drive

Skiff Drive is an end-to-end encrypted cloud storage service supporting file uploads, directory management, and shareable links. Uploaded files are chunk-encrypted in the browser before transmission — Skiff's servers only store encrypted data blocks. Drive is deeply integrated with Mail, allowing users to attach Drive files directly within the compose interface.

Skiff Calendar

Skiff Calendar is an end-to-end encrypted calendar application supporting event creation, shared calendars, and scheduling. Calendar data uses the same zero-knowledge encryption — event titles, descriptions, and participant information cannot be read by Skiff's servers. Calendar shares the same encryption system as all other Skiff products.

Limitations

• Post-Acquisition Uncertainty: Following Notion's acquisition in 2024, new user registrations have been suspended, and the long-term product roadmap remains unclear. Consider alternatives like ProtonMail for guaranteed continuity.
• Smaller User Base: Skiff's user base (under 500K) lags far behind ProtonMail's 100M+ users, resulting in fewer third-party integrations and a less mature app ecosystem. Some advanced features remain under development.
• No Bulk Email Sending: Skiff is positioned as personal privacy email — it does not offer SMTP relay, email APIs, or bulk marketing email capabilities, making it unsuitable for business email sending scenarios.
• Limited Mobile Experience: The mobile app covers fewer features than the web version; certain collaboration functions (like Pages Kanban view) have a restricted experience on mobile.

Use Cases

• Privacy-Sensitive Personal Email (★★★★★): End-to-end encryption and zero-knowledge architecture ensure only sender and recipient can read email content. Ideal for journalists, lawyers, activists, and anyone with strict communication privacy requirements. See Email Service Selection Guide.
• Encrypted Document Collaboration (★★★★): Skiff Pages provides end-to-end encrypted document collaboration, suitable for small teams that need to securely share sensitive documents.
• Censorship-Resistant Communication (★★★★): Decentralized storage and end-to-end encryption give Skiff strong censorship resistance, useful for users in regions with strict internet censorship.
• Business Email Sending (★): No bulk sending or SMTP relay capability — unsuitable for enterprise marketing or transactional email. For these needs, consider SendGrid or Amazon SES.

Pricing

Note: Pricing above reflects the pre-acquisition structure. New user registration has been suspended following the Notion acquisition; existing users continue to receive service, though future adjustments are possible.

FAQ

• Can I still use Skiff after the Notion acquisition? Existing users can continue using Skiff services, but new user registration has been suspended. Notion has stated it will integrate Skiff's encryption technology into the Notion platform — specific integration plans and timelines have not been announced. For alternative options, refer to Encrypted Email Comparison.

• How does Skiff compare to ProtonMail? Both offer end-to-end encryption and zero-knowledge architecture. ProtonMail is headquartered in Switzerland under Swiss privacy law protection, with a larger user base and more mature ecosystem. Skiff's advantage lies in its all-in-one private workspace (email + documents + storage + calendar). For a full comparison, see Encrypted Email Comparison.

• Can Skiff send emails to non-Skiff users? Yes. Emails to non-Skiff recipients can be shared via temporary passwords or secure links. The recipient uses a temporary password to decrypt and view the content. Security depends on the temporary password delivery channel — it is recommended to communicate temporary passwords through an independent channel (e.g., SMS or phone call). See Business Email Service Guide.

• Does Skiff support custom domains? Yes, custom domain email is available on the free tier via MX record DNS configuration. Pro plan users can also create unlimited email aliases. See SMTP Configuration Guide.