S/MIME Everywhere Client (U.S. only)
export restrictet

makes keys for digitally signatures and certificates, strong encryption.

WorldSecure Client is an S/MIME-compliant cc:Mail plugin. WorldSecure Client allows you to encrypt and digitally sign your outbound messages and read inbound messages that have been digitally signed and encrypted for you.
WorldSecure Client is integrated with cc:Mail. A Security menu is added to the Mailbox window and the message windows, providing easy access to security features.

WorldSecure Client Help ©1998 Worldtalk Corp.

(demo? but works still after the timelimit!!)