Security Bulletin MS11-100 was released at the end of last year and the Exchange Team informed the users that they have finished testing on Exchange 2010/2007/2003 running on either 2008 R2, 2003 and 2008 and the recommendation is to update the affected servers.
More information at source: http://blogs.technet.com/b/exchange/archive/2012/01/05/microsoft-security-bulletin-ms11-100-and-exchange-server.aspx
Cheers,
Anderson Patricio
http://blogs.msexchange.org/patricio
Twitter: @apatricio
