BrowseGate NAT/Proxy Server
This intranet and Internet e-mail server offers single and multiple e-mail domain support, a built-in user configurable anti-spam system. It has user and domain aliasing, routing, filtering and connection scheduling. You can perform remote administration using simple e-mail and set up permanent connections for ADSL and cable modems. It also works with all types of dial-up connections with automatic SMTP mail collection and from multiple POP3 mailboxes.
The license of this software is Free Trial Software, the price is $44.95, you can free download and get a free trial.