Yes, email2 can work alongside PKI based systems currently in place to provide an additional layer of privacy and protection while enhancing email functionality with features like auditability, retrievability, tracking and policy control.
email2 uses a different approach to ensuring that messages are delivered in secure and trustworthy manner.
With email2, data is protected because it is sent across secure HTTPS connections instead of transparent SMTP/POP3/IMAP4 ones. In addition, connections exist directly between the user and the PEN - messages are not bounced to multiple random routing servers in the meantime. Using email2 together with the latest in PKI encryption technology is an excellent way to maximize the security of your email system.
// Edited July 2008