It's completely transparent. Runs as a small icon on your system tray. Will obey shutdown and terminate signals from Windows correctly. SMTP server can be accessed from a set of IP ranges specified. Unlimited mail size.
Administrator can control the server, and do the maintenance of users.
Built in alias mail routing and forwarding functions. Bounce function when receiving messages to non-existing local accounts. Supports two languages in subscription database, and when sending Newsletters. All subscription text can be customized, including variabels - Internal editor. Auto transponder replies to those which has requested a recipt.