http://blogs.technet.com/b/exchange/archive/2007/09/21/3403958.aspx

http://blogs.technet.com/b/jmayans/archive/2006/09/07/454716.aspx

http://technet.microsoft.com/en-us/library/bb332063(EXCHG.80).aspx#Scenario4

http://technet.microsoft.com/en-us/library/cc178996.aspx

http://support.microsoft.com/kb/2028193