As the leading messaging system in use in the workplace today, Microsoft Exchange is the target for a number of companies that are advertising a lower cost of ownership, better performance, greater server loading or any of a number of other advantages. One of those companies is PostPath, which offers a Linux-based alternative to Exchange that the company claims is the “only drop-in and plug-compatible alternative to Microsoft Exchange.”

The PostPath Server’s numbers are impressive: on a Pentium-based server using LoadSim, PostPath’s performance was significantly better than Exchange, although PostPath admits that a wide variety of factors can influence messaging server performance.

That said, PostPath offers a number of capabilities in addition to very good performance, including automated failover capabilities, archiving capabilities, very nice backup and granular restoration capabilities, and the ability to use low-cost storage, among other capabilities.

PostPath Server also uses a PostFix mail transport agent and can used standards-based archiving systems without using Journaling. PostPath fully supports Outlook, but also includes an AJAX-based Webmail client that can be used with Internet Explorer, Firefox and Safari, making it suitable for use in Windows and Mac environments. The PostPath Webmail client can run on the same server as the PostPath Server itself, although this would likely be suitable only in smaller environments.

PostPath’s offering is impressive for a couple of reasons. First, it provides a viable alternative to Exchange for organizations that want to maintain Outlook on the desktop and use standard antivirus and other capabilities, but that don’t necessarily need to stay on the Microsoft roadmap for messaging. Second, the cost of ownership is lower than for Exchange. PostPath’s calculations show that for a 100-user environment, PostPath costs $117 per user vs. $298 for Exchange; for a 1,000-seat deployment, PostPath’s calculations show its cost to be $74 per user vs. $161 for Exchange.

PostPath is definitely worth a look for organizations that are not considering migrating to Exchange 2007 and for other organizations that are looking for a high performance server that provides a very reasonable cost of deployment and ongoing cost of ownership.

Michael Osterman is principal analyst of Osterman Research.