Signing or encrypting messages

After you have added your certificate, you can sign or encrypt a message by selecting Options ▸ S/MIME Sign or S/MIME Encrypt from the message composer menu or clicking the corresponding toolbar icon.

The Subject line of the message will not be encrypted and should not be used for sensitive information.

To have every message signed or encrypted:

  1. Select Edit ▸ Preferences ▸ Mail Accounts.

  2. Select the mail account to encrypt the messages in.

  3. Click Edit.

  4. Click the Security tab.

  5. In the Secure MIME (S/MIME) section, click Select next to Signing Certificate and specify the path to your signing certificate, or click Select next to Encryption Certificate and specify the path to your encryption certificate.

  6. Select the appropriate options.

  7. Click OK.