No, additional software is not required.
email2 is offered as an ASP, on-demand hosted solution. While we or your local technology reseller host your Private Email Network, we don’t replace any of the basic email infrastructure you currently have in place. Once sent or retrieved, email2 messages are stored behind your firewall as any other email message. Your company retains total and singular control over all of its own data.
// Edited July 2008