gpg4o is an add-in for Microsoft Outlook 2010/2013/2016® , which can be used to encrypt and decrypt, sign and verify messages and their attachments. gpg4o uses GnuPG, a free encryption software.

gpg4o uses an asymmetric encryption method and follows the OpenPGP standard. This system uses key pairs consisting of a private and a public key. The private key is kept secret, while the public key is passed on to one’s contacts. As soon as the public key of the other person has been obtained, an e-mail message can be encrypted with it to the recipients concerned. This message can then only be decrypted again with the private key of the recipient. For information on how to send and receive encrypted and signed files, please refer to the manual.

gpg4o requires Microsoft Outlook 2010®, Microsoft Outlook 2013® or Microsoft Outlook 2016® and an installed version of GnuPG v1.4.21 or higher. Starting with version 3.2, the installation of GnuPG is integrated into the setup of gpg4o. The necessary installation files can be found in the download area of gpg4o. The steps necessary for the installation are described in the manual. Windows 7® (32/64 bit), Windows 8® (32/64 bit) or Windows 10® (32/64 bit) can be used as operating system. For detailed information, please refer to the System Requirements page.

If the trial period is not sufficient for you, we will be happy to extend it. Contact us at [email protected] You can still read your messages encrypted with gpg4o as long as you do not uninstall gpg4o. As soon as you have purchased a license for gpg4o and imported it, gpg4o is fully usable again within the scope of the purchased license without further installation.

When importing a license file, “No license file” is displayed or a license file, as an attachment to an e-mail, cannot be imported. In case of these errors, we recommend that you check whether you have installed GnuPG correctly and have specified the path to gpg.exe/gpg2.exe correctly in the settings. If necessary, reinstall GnuPG on your computer.

If you have deleted the account with the licensed e-mail address in Outlook, gpg4o no longer recognizes your current license because the associated e-mail account is deleted and goes into test version mode. You must now create and import a new license with your new email address in the license management. After that you will have a fully functional gpg4o again.

I receive the license from the license management by e-mail and I cannot import it. The following error message appears: “Your license does not match the current Outlook account. Please adjust your license in the gpg4o license management or contact the sales department.” Check whether the e-mail address in your Outlook is identical to the e-mail address in the license. The two e-mail addresses must be consistent. If this is not the case, correct the e-mail address of your license via the gpg4o license management.

What can a license from gpg4o? During the term of the product maintenance you have the possibility to use the support in case of questions or problems and to obtain and install updates. Each license of gpg4o may be used simultaneously on multiple computers and in different profiles (e.g. desktop PC + laptop) as long as the licensed e-mail address is set up in Outlook on both computers. The product maintenance period and the license usage period start with the first download of the purchased license. If you intend to use gpg4o with different profiles within the same Outlook installation, please contact us.

If the product maintenance/support has expired, gpg4o can still be used. This means you can still send encrypted/signed emails and read encrypted/signed emails. However, you will no longer receive updates from gpg4o.

By purchasing a product maintenance/support extension, you can continue to receive new updates for gpg4o. The gpg4o developer team is constantly improving the program and integrating suggestions from customers into a new version. After purchasing an extended license, it must be imported into gpg4o once.

When updating gpg4o, only the program files are updated. Your GnuPG keychain and your settings from gpg4o will be taken over.

Install gpg4o as local administrator.

Yes, import and export of keys is also possible via drag ‘n drop.

Yes, gpg4o supports encrypted e-mails in HTML format.

gpg4o uses the PGP/Inline procedure for sending encrypted e-mails. The PGP/MIME format is supported in read-only mode.

When you send an e-mail and activate the options for “Encrypt” and/or “Sign”, these settings apply to both the text of the e-mail and its attachments. Only the subject line and the recipient list remain unencrypted. If desired, gpg4o will only encrypt the attachment of a message.

If your computer is defective, you will no longer have access to your hard drives. You will also no longer be able to access the private keys, so you will not be able to decrypt any old e-mails encrypted with these keys. To protect yourself from this, please create a backup. Save the backup only on your own physical media. The backup contains your personal data, so you should never upload the backup to the cloud.

Do you have questions about discounts for different customer groups (dealers, pupils and students, educational institutions or non-profit associations)? Do you have questions about the graduated prices of the individual products? If you have any problems or questions regarding the purchase of gpg4o, please use the contact form or send an e-mail to [email protected]

If any problems or questions arise during the installation or use of gpg4o, please follow the instructions on the support page. If an error occurred, please remember to attach the automatically generated log file. You will help us if you describe observed errors as accurately as possible, indicating what steps you took before the error occurred.

So that our development department can eliminate any errors that may occur as efficiently as possible, status messages from gpg4o are written to so-called log files. These status messages do not contain personal information, passwords or contents of e-mails. Before sending the e-mail with the log files, you can view the transmitted information by unpacking the attached .zip file. All files contained in it consist of plain text.

The “Hide attachment names” option is enabled by default in gpg4o and increases – by hiding the file name – the confidentiality of your e-mails. If a recipient cannot process these file names, you can deactivate this option in the gpg4o settings. In gpg4o in the “Settings”/”Send/Receive Settings”/”Send -Attachment Sending Options” you can activate the option “Keep attachment names”, this increases the compatibility with other OpenPGP implementation.