Choose Options in the FILE menu, click the "Trust Center" tab and click the "Trust Center Settings" button at right panel. At Trust Center, Click "E-mail Security" tab and click "Settings" at the right panel. Make sure to select the email certificate that was just imported at "Signing Certificate:" tab and then press OK.
At the right panel of the "E-mail Security" Tab, you can click "Add digital signature to outgoing messages" to automatically sign every message that you send. To have the best compatibility with your recipients, we recommend that you also select the "Send clear text signed message..." as well.
If you would like all emails to be encrypted when they are sent, click "Encrypt contents and attachments for outgoing messages".
Click OK when you are finished. Your VikingCloud Secure Email Certificate is now completely installed.