No major conclusions / info in the short report summary. However this report is a good read (for those who have a Gartner subscription / can afford it) if your business is email / calendaring / UC …
… Aided by unified communications initiatives, the enterprise e-mail and calendaring software market is being revitalized. New versions from IBM and Microsoft, as well as new offerings from Google, Linux-based, and open-source-based vendors, are providing more choice and driving growth. …
Source: Forecast: Enterprise E-Mail and Calendaring, Worldwide, 2006-2011
Related report :
Market Share: Enterprise E-Mail and Calendaring Software, Worldwide, 2004-2006
… The enterprise e-mail and calendaring software market is entering a transitional phase. While IBM and Microsoft still dominate this market, with approximately 90% share based on total software revenue, new hosting-only vendors, Linux and open-source-based e-mail offerings are now making inroads. …