What is OpenPGP?

What is OpenPGP?

OpenPGP is an open standard for end-to-end encrypted email communication (RFC 4880). eclipso Mail Europe is the only German email provider offering native OpenPGP encryption in all plans - including freemail - without additional costs or complicated setup.


OpenPGP encryption is available in all plans. Freemail users receive 1 key pair for free, Premium users can manage multiple keys for different email addresses.
 

• What is OpenPGP?

  • OpenPGP (Pretty Good Privacy) is an international standard for email encryption.
  • Your messages are end-to-end encrypted - only you and your recipient can read the content.
  • The standard has existed since 1997 and is used worldwide by millions of users.
  • OpenPGP is client-independent: You can use Thunderbird, Apple Mail, Outlook (with plugin), or K-9 Mail.
  • Important: eclipso Mail Europe cannot read your encrypted messages - you retain full control over your data.

• How does OpenPGP work with eclipso?

  • 1. Key Generation (60 seconds): You create a key pair in the settings.
  • 2. Automatic Key Exchange: When you receive a signed email, eclipso Mail Europe automatically imports the public key of your contact.
  • 3. Encrypt & Sign: From now on, you can write encrypted messages - eclipso Mail Europe automatically handles encryption.
  • 4. Trust Levels: You can mark keys as "trusted" - just like in Thunderbird.
  • No Keyserver needed: Thanks to auto-import, you don't need to manually search or upload public keys.

• What makes eclipso Mail Europe different from other providers?

  • Free for Freemail: We are the only provider worldwide offering OpenPGP without a paywall (1 key free).
  • Native Integration: Encryption works directly in webmail - no browser extensions like Mailvelope needed.
  • Auto-Key-Management: Public keys are automatically imported and managed.
  • Thunderbird Compatibility: All features work identically to Mozilla Thunderbird (Trust Levels, Protected Headers, Sign-then-Encrypt).
  • All Clients supported: Use Thunderbird, Apple Mail, Outlook, K-9 Mail - everything works without "Bridge" or additional software.

• Technical Details

  • Standard: RFC 4880 (OpenPGP Message Format)
  • Encryption: RSA 2048/4096 Bit (selectable during setup)
  • Backend: GnuPG 2.2+ (Open Source, used by millions)
  • Passphrase Protection: Private keys are encrypted with Argon2id + AES-256-GCM
  • Compatibility: 100% compatible with all OpenPGP tools worldwide (Thunderbird, GPG CLI, Sequoia-PGP, etc.)
  • Protected Headers: Encrypted subject line is supported (RFC 8551)

• What can I do with OpenPGP?

  • Encrypt emails: Only the recipient can read your message
  • Sign emails: Prove that the email really came from you
  • Combine both: Encrypted AND signed (recommended for maximum security)
  • Encrypted subject: Even the subject line can be encrypted (Thunderbird feature)
  • Encrypt attachments: Documents, images, PDFs - everything is encrypted

• Getting Started

  • Log in to your eclipso Mail Europe account (Desktop version recommended for initial setup)
  • Open Settings > E-Mail | PGP Keyring
  • Click "Generate Key" and follow the 60-second wizard
  • Choose a secure passphrase (at least 12 characters)
  • Done! From now on you can receive and send encrypted emails
  • Tip: Back up your private key in a secure location (e.g., password manager like KeePass)

• Important Notes

  • Your passphrase is essential - without it you can no longer read encrypted emails!
  • eclipso Mail Europe cannot help you with a lost passphrase - this is a feature, not a bug (Zero-Knowledge principle)
  • Store your passphrase in a password manager (e.g., KeePass, 1Password, Bitwarden)
  • OpenPGP works in all email programs - test different clients!
  • Encryption is free - even for freemail users (1 key included)
  • GDPR-compliant: Your encrypted data stays in Germany and is only readable by you

• Difference from S/MIME

  • eclipso Mail Europe supports both encryption standards: OpenPGP AND S/MIME
  • OpenPGP: Free, no certificate authority needed, ideal for individuals
  • S/MIME: Certificate-based, established in enterprises, paid (approx. €50/year)
  • You can use both in parallel - choose based on your communication partner
  • More details: OpenPGP vs. S/MIME - What's the difference? ↗

• How do I set up OpenPGP encryption in 60 seconds? ↗
• What's the difference between signing and encrypting? ↗
• Using OpenPGP with Thunderbird ↗
• Solving common OpenPGP problems ↗