Klicken Sie in der Betreffzeile dieser signierten E-Mail mit der rechten Maustaste und wählen Sie «Zu Kontakten hinzufügen».Open the signed email message that you received from the recipient.Six steps to check the existence of the certificate / To ensure that a contact has been assigned a certificate in Outlook, do the following: To exchange encrypted messages, the sender and recipient must have a signature and encryption certificate. A signed email is the best way to distribute this certificate to those who want to send you encrypted messages. In order for Outlook to send an encrypted email to another person, a valid certificate must be assigned to the contact who is the intended recipient of the encrypted message. To ensure that the public key supplied with the message is actually related to the actual sender and is not just invented, Sectigo inserts its own signature in your certificate to secure your claim. So that a person who receives a digitally signed message can read it, your public key is sent with your message. These two people have the same ability and can now send each other's encrypted messages to each other using the other person's public key. In this case, anyone can send an encrypted (secret) message to one of these two people from anywhere. Secure bidirectional communication is achieved in that both sides have certificates and both parties give everyone their public key. Microsoft Outlook had problems encrypting this message because the following recipients had missing or invalid certificates or conflicting or unsupported encryption features.