Agent for Exchange can be installed in the following operating systems:
Windows Server 2003/2003 R2 – Standard and Enterprise editions (x86, x64)
Windows Small Business Server 2003/2003 R2
Windows Server 2008 – Standard, Enterprise, and Datacenter editions (x86, x64)
Windows Small Business Server 2008
Windows Server 2008 R2 – Standard, Enterprise, Datacenter, and Foundation editions
Windows Small Business Server 2011 – all editions
Windows Server 2012/2012 R2 – Standard and Datacenter editions