Linux Journal via Stephen Kelley:
Roughly a year ago I reviewed a mail server for Linux that features integration with Microsoft’s Outlook and offers calendaring/scheduling options with shared busy/free information. However, it did not have many features that Outlook offers in corporate mode, including sending meeting requests to groups of users who can then reply and delegating rights so secretaries can manage their bosses agendas on-line. This current review shows a year’s time was enough for Linux solutions to arise that can compete with Microsoft Exchange and Outlook and offer a lower price, with all the important features included.
The article covers Bynari InsightServer and Kroupware, but leaves out OpenExchange by Suse. Of the three, I’ve only seen OpenExchange in action, and it absolutely rocks. If you’re looking for an Exchange alternative, take a look at OpenExchange too.