Exchange 2007

1). Support Only 64bit version of windows
2). Standard and Enterprise edition
3). Exchange 2007 is better performance, voice mail integration, better search, support web service and the new
     interface feature of outlook web access
4).Exchange 2007 dropped - Exchange 5.5 migration tools, Admin group, Routing group, X400 and some API
    feature.
 
                         Standard         Enterprise
Storage Group-  up to 5             up to 50 
Database        -   max 5               max 50
Database Limit-  16TB                16TB