This article will tell you how to configure an email certificate on Outlook 2016. The instructions for installing certificates on other email clients are similar.

Preparation

1.     Your Email or S/MIME certificate

2.     Email client: Microsoft Outlook 2016

Importing your certificate into Outlook 2016

1.     Open Outlook 2016, then click File > Options

2.     In the Outlook Options screen, click Trust Center > Trust Center Settings

3.     In the Trust Center screen, select E-mail Security then click the Import/Export button.

4.     In the Import/Export Digital ID interface, navigate to the location of your PKCS12 certificate file and click Open.

      Enter the password that was used while exporting the certificate and provide a Digital ID name，and then click OK.

5.     Select the security level for storing the Private Key in your system and click OK.

Well done! You have successfully imported your email certificate into Outlook 2016.

Signing and Encrypting Mails

1.  Signing an email ensures the recipient knows the email has come from you and informs them that it has not been modified in transit.

2.  Encrypting an email ensures that only the recipient can read the email content and attachments.

Note: In order to encrypt mail, you must first have your recipient’s email certificate in your certificate store. To obtain their certificate, you need to get your contact to send you a signed email. Upon receipt of the signed mail, their certificate will be automatically imported into your certificate store and you will be able to sign/encrypt mail to that person.

It's time to assign the certificate.

1.     Open Outlook 2016, then click File > Options. In the Outlook Options screen, click Trust Center > Trust Center Settings.

2.     In the Trust Center screen, select E-mail Security then click the Settings button.

The Change Security Settings dialog allows you to choose signing and encryption certificates. In most cases you should be using your Email Certificate for both signing and encrypting.

3.     Click the two Choose buttons next to the Signing or Encryption Certificate field. A new window will appear which will allow you to choose your email certificate from the list of imported certificates. If you are not sure, you can highlight a certificate and click the View Certificate button to see certificate details.

Now you should see your certificate listed as the signing and/or encryption certificate fields.

4.     Click OK to return to the Trust Center screen.

Signing and encrypting individual emails

Firstly, compose an email or reply to an existing email. Then, click Options on the message menu bar and click one or both of the Sign and Encrypt buttons depending on your requirements.

When the email is sent, it will be signed and/or encrypted per the options selected.

Signing and encrypting all mails by default

      1.  Open Outlook 2016, then click File > Options Trust Center > Trust Center Settings

2.  Select E-mail Security

3.  To encrypt every message by default, check the Encrypt contents... box.

     To sign every message by default, check the Add digital signature... box.

As a rule of thumb, many users choose to digitally sign by default but only encrypt when sending a message which requires confidentiality.