Caldera's VARs, picked up with the acquisition of SCO last year, had a problem: Microsoft Exchange. Microsoft's notoriously complex mail server package was impractical for small and mid-sized businesses, but in order to sell those customers on a replacement, VARs had to offer compatibility with the shared address books and calendars that are part of the popular mail client Microsoft Outlook.

"The whole Exchange thing has been holding people hostage", said Caldera software architect Louis Imershein. The problem wasn't stability or price, but the need for an expensive Microsoft Exchange-certified consultant to deploy even a small or mid-sized mail server.

The solution is Caldera's Volution Messaging Server, which combines SMTP, IMAP, POP and web mail in a single, web-administered package licensed for $28 per seat. "Users don't know it's not Microsoft Exchange", Imershein said. And from the administrator's point of view, the skills to be mastered are simpler than those in the thick MS Exchange manuals.

For example, a simple "block all executable attachments" policy for virus protection is much easier to set up under Volution Messaging Server than under MS Exchange, Imershein said.

Volution Messaging Server's Basic calendaring features are compatible with those of Microsoft Outlook, and the package provides a common LDAP address book for an entire company. Say "Outlook" and any sensible sysadmin or VAR will think virus protection. Volution Messaging Server includes virus checking integration, and Sophos, popular with Caldera VARs, has begun to support it.

Another vendor already offering an add-on is Steltor, with two products, Steltor Corporate Time Server and Outlook Connector, that provide more advanced calendar features.

Under the hood, Volution incorporates three key open-source packages: OpenLDAP, the Postfix MTA, and Cyrus for IMAP and POP. Caldera's additions, licensed under viewable source terms, include the web-based admin tools and a flexible alias management system.

Users may be given rights to create and manage MTA aliases, so any user with permission to do so can start a project and set up a mailing list. Or the webmaster can create special-purpose addresses for response to web pages without having to go through the mail system administrator. The alias management system has been used in-house at SCO since the 1990s, where is started off as an IT department tool. Before Caldera bought SCO, employees depended on the system but didn't think of making it available to customers, too.

Caldera Volution Messaging Server

Sophos Anti-Virus for UNIX

Steltor Products

Don Marti is the Technical Editor of Linux Journal.