MailScan 4 for Microsoft Exchange Server is the world's first "Real-Time" e-mail scanner for the Microsoft Exchange Server. It acts like a Content-Security and Anti-Virus Software between your Corporate Exchange Mail Server and the Internet. It has the world's first "real-time", e-mail Content-Security and Anti-Virus feature that analyzes e-mails before they are delivered to the clients or the servers on your network. Support 24/7.