To set your secure e-mail settings, do the following:
Select Tools, Options, select the Security tab, and click the Settings button. The Change Security Settings dialog opens, as shown in Figure 18.5.
Figure 18.5. The Change Security Settings dialog.
Enter a name for the settings you are creating and leave the Cryptography Format setting as S/MIME. S/MIME (Secure Multipurpose Internet Mail Extension) is a widely supported Internet standard for secure e-mail and is the protocol Outlook uses for secure e-mail.
Check the Default Security Setting for this cryptographic message format checkbox.
Check the ...