Security at enemail

Your email is yours alone.

We built enemail so that even we cannot read your messages. Not because we have to — because it's the only way privacy should work. Here's exactly how.

AES-256 Symmetric encryption
RSA-4096 Key exchange
Zero Knowledge architecture
100% EU Server infrastructure
Architecture

Zero-knowledge — by design

Zero-knowledge means that enemail's servers only ever store ciphertext — encrypted data that is mathematically impossible to read without your private key. Your private key never leaves your device in readable form.

When you log in, your password is used to derive a key locally on your device. That key decrypts your private key locally. The decrypted private key then decrypts your emails — all in your browser or app, never on our servers.

  • enemail cannot read your emails
  • We cannot hand over readable content to authorities
  • A server breach exposes only encrypted data
  • No employee can access your mailbox
Your device
Encrypted only
enemail server
🔒 Private key never reaches the server
Encryption Standards

Military-grade cryptography. Open standards.

We use only well-established, peer-reviewed algorithms. No proprietary "black box" encryption — everything can be independently verified.

AES-256-GCM

Email content is encrypted with AES-256 in Galois/Counter Mode. GCM provides both confidentiality and authentication — tampered ciphertext is detected and rejected.

Symmetric encryption

RSA-4096

Asymmetric key pairs use 4096-bit RSA. Your public key encrypts the session key; only your private key can decrypt it. Brute-forcing a 4096-bit key is computationally impossible.

Key exchange

bcrypt / Argon2

Your password is never stored. It's processed through Argon2id (memory-hard key derivation) before being used to encrypt your private key. Even with server access, passwords cannot be recovered.

Password security

TLS 1.3

All data in transit is protected with TLS 1.3 — the latest and most secure transport protocol. Older, vulnerable versions (TLS 1.0/1.1, SSL) are disabled entirely.

Transport security

PGP / OpenPGP

Full PGP support for encrypted communication with non-enemail users. Import/export keys, sign messages, and communicate with the global PGP ecosystem.

Interoperability

Forward Secrecy

Each email session uses ephemeral keys. Even if a long-term key is ever compromised in the future, previously encrypted messages remain secure and unreadable.

Session security
Account Security

Two-factor authentication

Zero-knowledge encryption protects your email content — but your account login is a separate attack surface. We provide multiple second-factor options so that a stolen password alone is never enough to gain access.

We strongly recommend enabling 2FA on every account, and require it by policy for all team and business plans.

  • Time-based OTP (TOTP) — works with any authenticator app
  • Hardware keys (YubiKey / FIDO2 passkeys) — coming Q2 2025
  • Trusted device memory — skip 2FA on known browsers
  • One-time backup codes for emergency account recovery
📱

TOTP App

Works with Aegis, Google Authenticator, Authy, 1Password, and any RFC 6238-compliant app.

Live now
🔑

Hardware Security Key

YubiKey, Nitrokey and FIDO2 passkeys — the strongest possible second factor against phishing.

Q2 2025
🖥️

Trusted Devices

Mark a browser as trusted after successful 2FA to avoid repeating the check on every login.

Live now
📋

Backup Codes

Ten one-time recovery codes generated at 2FA setup. Store them somewhere safe offline.

Live now
Infrastructure

Your data never leaves Europe

enemail runs exclusively on dedicated bare-metal servers by Evolushost located in Frankfurt, Berlin, and Vienna. No shared cloud, no US hyperscalers, no jurisdictional grey areas.

Dedicated hardware means no noisy neighbours, no hypervisor attacks, and no cloud provider able to image your server. Physical access is restricted and monitored 24/7.

Frankfurt, Germany
Berlin, Germany
Vienna, Austria

Austrian jurisdiction · GDPR · No US CLOUD Act exposure

EU Data Centres
3 / 3 online
Berlin DE-1 · Online Frankfurt DE-2 · Online Vienna AT-1 · Online
🇩🇪 Berlin ● Online
Node DE-1 · Germany
🇩🇪 Frankfurt ● Online
Node DE-2 · Germany
🇦🇹 Vienna ● Online
Node AT-1 · Austria
Threat Model

What we protect you against

Being honest about what a security system can and cannot do is part of good security. Here's our threat model.

Protected against

  • Mass surveillance and bulk data collection
  • Data breaches — servers hold only ciphertext
  • enemail employees reading your email
  • Weak legal requests (our jurisdiction requires strong legal basis)
  • Email content interception in transit (TLS 1.3)
  • Password database leaks (passwords are never stored)
  • Advertising profiling and data monetisation

Limitations to understand

  • If your device is compromised, your emails can be read (device security is your responsibility)
  • Email metadata (who you communicate with) requires additional protection
  • Emails to non-encrypted providers (Gmail, etc.) are delivered unencrypted on their side
  • A forgotten password means lost access — we cannot recover it
  • Sophisticated nation-state attackers with physical device access
FAQ

Security questions, answered honestly

The most common questions we get about how our security actually works — including where its limits are. We believe honesty about limitations is part of good security.

No. Your emails are encrypted on your device using your private key before any data reaches our servers. We only ever store ciphertext. Even if an enemail employee had full database access, they could not read your messages — it's a mathematical impossibility, not a policy. This applies to emails both in your inbox and in your sent folder.

If we received a legally valid court order, we could provide the encrypted data we store — timestamps, sender/recipient addresses (metadata), and ciphertext. We cannot provide readable email content because we don't have it. As an Austrian company, any data request must follow EU and Austrian law — we do not cooperate with foreign law enforcement requests that bypass this process. We publish the number of requests we receive annually in our transparency report.

Your password is used to derive the key that encrypts your private key. Because we never store your password or private key, we have no way to recover access to your account. This is a fundamental property of zero-knowledge encryption — and it means you must keep your password safe. We recommend using a password manager. A forgotten password means permanent loss of access to past emails. Future emails to your address can continue once you reset your account, but old encrypted content cannot be recovered.

Even in the event of a complete server breach, an attacker would only obtain encrypted ciphertext, metadata (sender/recipient, timestamps), and hashed authentication data. Your actual email content would remain unreadable without your private key, which is never stored on our servers. We would notify affected users as required under GDPR (within 72 hours of discovery). This is why zero-knowledge architecture matters — a breach should be embarrassing, not catastrophic.

Emails are encrypted in transit via TLS 1.3 between mail servers. However, once delivered to Gmail or another non-encrypted provider, those providers can read the email content — that's how their systems (and advertising models) work. End-to-end encryption only works when both parties use an encrypted email service, or when the recipient's public PGP key is available. We support PGP, so you can send encrypted emails to any user who has published a PGP key — regardless of their email provider.

No. Your private key is generated on your device and is encrypted with a key derived from your password before being uploaded. We store an encrypted version of your private key to allow you to log in from multiple devices — but we cannot decrypt it. Your public key is stored in plaintext so other users can send you encrypted messages. In summary: we hold your encrypted private key but have no ability to decrypt it.

Transparency canary

Warrant canary

A warrant canary is a statement that we publish as long as certain things have not happened. If this statement stops being updated, or if these items are removed, interpret that as a signal that the situation has changed.

This canary is reviewed and re-published each quarter by the Evolus IT Solutions GmbH team.

Last updated: Q2 2025
We have never received a National Security Letter, gag order, or FISA court order of any kind.
We have never been compelled to install a backdoor or weaken our encryption for any authority.
We have never disclosed decrypted email content to any government or third party.
We have never been subject to a search or seizure of our servers without legal process compliant with EU law.
enemail infrastructure has never experienced a data breach resulting in exposure of user content.

Found a vulnerability? Tell us.

We take security reports seriously. If you discover a security vulnerability in enemail, please report it responsibly. We commit to acknowledging reports within 48 hours and to working with researchers to resolve issues before public disclosure.

We are building a formal bug bounty programme. In the meantime, please reach out directly.

security@enemail.de

PGP-encrypted reports welcome

Privacy backed by real cryptography.

Not promises. Not policies. Mathematical guarantees.