Step 1: Install certificate files
Open and install all the certificate files you received. Before installing your private certificate, you will need to enter the installation password.
Step 2: Restart Apple Mail
After successfully installing all certificate files, restart Apple Mail
Step 3: Sending encrypted email
After restarting Apple Mail you will see two new icons when composing an email.
- The lock icon denotes an encrypted email. This message is encrypted with the recipient's public key and can only decrypted using his private key.
- The right icon denotes a signed email. This means that your own public certificate will be attached and the recipient can use it to send you an encrypted email.
Both options should be enabled.