A bit of love from Network World…
Exchange alternatives: Pros and cons
Testing shows Microsoft's Exchange still tops for features and management hooks @http://www.networkworld.com/reviews/2009/030909-exchange-alternatives-test.html
“In this Clear Choice Test, we explore how Exchange alternatives stack up against Microsoft's offer, as well as each other.
Our testing focuses on products for midsized deployments of 1,000 mailboxes or less. We tested six Exchange alternatives: CommuniGate Pro (CommuniGate Systems), Kerio MailServer (Kerio Technologies), MDaemon Pro (Alt-N Technologies), MailSite Fusion (MailSite), Scalix Enterprise Edition (Scalix, a Xandros company), and Zimbra Collaboration Suite, Professional Edition (Zimbra, a Yahoo company).”
“While there are places where our Exchange alternatives outdo Exchange -- such as in price/performance, Macintosh interoperability, and manageability for mid-sized deployments -- Exchange still beats the competition in many areas because it offers a range of features that aren't easy to find in the third-party market.”
But no Notes\Domino?
..and whilst we’re on the subject:
Comparing Microsoft Exchange Server 2007 to Other Messaging Solutions
Case Studies About Microsoft Exchange Server 2007
Alternatives to Microsoft Exchange
Exchange Server 2007: First-Class Mail