The central functions of gpg4o at a glance. See for yourself.

Email encryption
  • Asymmetric encryption method
  • Private and public keys
  • Encryption by both keys
  • Readable only with private key
  • Confidential communication guaranteed
Outlook integration
  • Simple and secure
  • Seamless user experience through integration in Outlook
  • Encryption and decryption of messages and attachments
  • End-to-end encryption
  • Compatibility and widespread standard: Based on OpenPGP with a global user base
Key Server Management
  • Simple key distribution thanks to automatic synchronization
  • Exchange keys with local and public key servers
  • Central key management (requires Enterprise KeyServer)
  • Web of Trust – checking the trustworthiness of external keys using information from known key holders


Support for key servers
Support for terminal servers
Microsoft Policy Manager and automatic key generation
Compatibility with Symantec Encyption (formerly PGP), Enigmail, KMail, Apple Mail, K9-Mail and iPGMail and more
Large user base (OpenPGP)
Support for working groups
Strong cryptography
Strong performance

System requirements

gpg4o® was developed for Microsoft Outlook® 2013/2016/2019/365 and Microsoft Windows®. The following combinations are supported:


Operating system Outlook 2013 Outlook 2016 Outlook 2019 Outlook 365
Windows 7
Windows 7 (Service Pack 1)
Windows 8
Windows 8.1
Windows 10
Windows 11
Mac OS

Svenja Winkler

How to contact us

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