Using the Guard

Encrypting E-Mail Conversations

3.2.3. How can external recipients read an encrypted E-Mail?

You can also send encrypted E-Mail messages to external recipients who are not groupware users. When adding an external recipient, Guard checks whether a public key is available for this recipient. Depending on the result, Guard uses different procedures for sending the encrypted E-Mail.

  • If there is a public key for the recipient:

    • The message is encrypted and sent with this key. The recipient can read the message with his/her private key.

    • To enable the recipient to send an encrypted reply, your public key is sent as an attachment. The attachment is called public.asc. The recipient can import this key to his/her E-Mail client.

  • If there is no public key for the recipient:

    • If the external user already has a guest account, he/she receives an E-Mail with the link to the login page of his/her guest account. When having logged in, he/she can read the encrypted E-Mail on the guest page. He/she can send an encrypted reply from this page.

    • If there is no guest account, a guest account will be created. The external recipient receives an E-Mail with some guidelines and an automatically created password. He/she receives an additional E-Mail with the link to the guest page. On the guest page, he/she logs in with the automatically created password. Then he/she can create a password.

    • Depending on the groupware configuration, guest account E-Mail messages are deleted after a specific number of days. To still make those E-Mail messages available, the E-Mail with the link to the guest page contains an attachment with the encrypted E-Mail. The attachment is called encrypted.asc. This attachment can be uploaded and read on the guest page.