Email encryption made easy

Encrypt emails in a simple, user-friendly and yet secure way – seamlessly integrated into the Microsoft Outlook user interface with gpg4o.

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Secure email encryption directly in Outlook

Encrypt emails in a simple, user-friendly and yet secure way? With gpg4o this is possible. gpg4o is an add-in for email encryption in Microsoft Outlook 2013/2016/2019® and integrates seamlessly into the user interface. From here, messages and their attachments can be securely encrypted as well as decrypted, signed and verified. The clever end-to-end encryption system is easy to install and simple to use. gpg4o is based on the OpenPGP standard with millions of users worldwide and is compatible with many encryption programs.

Why email encryption?

Whether at work or in our private lives, we exchange data with other people by e-mail every day. As a rule, we think nothing of it and are pleased that electronic messages can be sent so conveniently, quickly and cheaply. But technically speaking, e-mails are nothing more than virtual postcards that can easily be intercepted, read and manipulated by anyone on their way from the sender to the recipient.

How does e-mail encryption work with gpg4o?

gpg4o uses an asymmetric encryption method for e-mail encryption. This system uses key pairs consisting of a private, i.e. secret, key and a public key. The recipient’s public key is used to encrypt the e-mail. This can then only be decrypted again with the recipient’s private key.

Not only the data is lost…

For companies, this can have far-reaching consequences. The loss of sensitive project, personnel and financial data can not only damage a company’s image, but may also result in a financial loss or even destroy a competitive advantage. And private information can also be of interest to third parties and misused.

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Services and functions at a glance

Email encryption made easy
- Encrypt and sign emails easily
- Sign attachments as well as encrypt and decrypt them
- Support for distribution lists and Exchange groups – Individually configurable sender rules (e.g. “Always encrypt to…”)
Clear key management
- Exchange keys with local and public key servers
- Web of Trust – check trustworthiness of foreign keys using information from known key holders

Large user base: use of the worldwide standard OpenPGP
- Compatible with many other encryption programs such as Symantec Encryption (formerly PGP), Enigmail, KMail, Apple Mail, K9 Mail and iPGMail
- Supports international character sets
- Strong cryptography using elliptic curves: greater security, more speed, smaller keys

Safety is the highest goal

Whether at work or in our private lives, we exchange data with other people by e-mail every day. To ensure that sensitive messages are protected from the eyes of attackers, they need to be protected accordingly. And the best way to do that is simple, user-friendly and secure. Encrypt your email traffic now with gpg4o.

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Application of gpg4o

How to work with gpg4o®? An example from practice.

In the following example, Mr. Mustermann would like to seal the cooperation on a project with Mr. Doe. To do this, he writes an e-mail that contains project internals such as the description of the project and the access data. Furthermore, Mr. Mustermann adds an attachment with sensitive files. It goes without saying that both parties are interested in ensuring that this e-mail traffic cannot be traced by unauthorized persons. Therefore, this e-mail is encrypted with gpg4o.

By using gpg4o, it is made impossible for a third party to read the e-mail, even if they should manage to intercept it. You as the user are relieved of the work of having to take care of the encryption principle yourself. All you have to do is exchange your public keys with your communication partner once. Once this has been done, you can conveniently select whether the e-mail is to be encrypted and/or signed. The rest is done automatically for you by gpg4o.

Which gpg4o version suits you?

gpg4o is equally suitable for companies and private individuals for secure email encryption. Since the installation, administration, archiving and data backup requirements of companies are very specific and complex, we offer a slimmed-down and free version, gpg4o Free, for private individuals in addition to the full version.

For companies: The gpg4o full version

The gpg4o® full version is primarily intended for companies but also for technically experienced users who want to benefit from extensive functions and our support. Enjoy the benefits of our large user base and clear key management. with functions specially designed for companies

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gpg4o® Free for private users

For private users we offer our email encryption add-in gpg4o as a free freeware version: gpg4o Free. This provides all private Outlook users with end-to-end encryption, which has been tried and tested in numerous companies, free of charge. The freeware has as its goal to further promote the widespread use of encryption in people’s everyday lives

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System Requirements

gpg4o was developed for Microsoft Outlook® 2010/2013/2016/2019 and Microsoft Windows®. For details about the platforms supported by BAYOOSOFT, please refer to the following table.

Operating System
Windows 7
Windows 7 (Service Pack 1)
Windows 8
Windows 8.1
Windows 10
Mac OS

Outlook 2010
✔
✔
✔
✔
✔
✖

Outlook 2013
✔
✔
✔
✔
✔
✖

Outlook 2016
✖
✔
✔
✔
✔
✖

Outlook 2019
✖
✖
✖
✖
✔
✖

Contact us now

In order to make your e-mail traffic secure, we are happy to support you with competence and experience

Email encryption made easy

Secure email encryption directly in Outlook

Why email encryption?

How does e-mail encryption work with gpg4o?

Not only the data is lost…

Services and functions at a glance

Safety is the highest goal

Application of gpg4o

Which gpg4o version suits you?

For companies: The gpg4o full version

gpg4o® Free for private users

System Requirements

Contact us now

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