From Linux Journal:
"Linux is making progress in many server areas. For instance, I have a Mitel (formerly e-smith) server at home that serving files and printers with
Samba and doing firewall and web server duties as well. One of the newest addition to the server arena came when Caldera launched Volution Messaging
Server (VMS). VMS features integration with Microsoft's Outlook and offers calendaring/scheduling options with shared busy/free information, SSL
support for e-mail and easy configuration."
May 4, 2002
Caldera Volution Messaging Server: a product review