Move over Exchange, Notes - Zimbra is better (and much cheaper)
Ask for your Zimbra free trial!
Zimbra Collaboration Suite is an enterprise-class open source email, calendar and collaboration server. With the most innovative web application available today, Zimbra boosts the productivity of users on any desktop and dramatically reduces TCO compared to legacy platform vendors.
Other key advantages include advanced compatibility with existing desktop email clients, over-the-air sync to smartphones (iPhone, Android, BlackBerry) as well as better server scalability and more efficient administration.