Microsoft Exchange Server 2010 helps you achieve new levels of reliability and performance by delivering features that help to simplify your administration, protect your communications, and delight your customers by meeting their demands for greater business mobility
Read more at source: http://blogs.technet.com/b/exchange/archive/2013/02/12/released-exchange-server-2010-sp3.aspx
Download it from there: http://www.microsoft.com/en-us/download/details.aspx?id=36768
Cheers,
Anderson Patricio
http://www.andersonpatricio.ca
http://www.andersonpatricio.org (Portuguese)
Twitter: @apatricio