Have you recently installed Exchange 2013, to later need to install CU1 to support down level servers such as Exchange 2010. Guess what?
Cumulative Update 2 (RTM) for Exchange Server 2013 has been released to the wild. In this update we expect to have resolutions to issues that were found in Exchange Server 2013 CU1 since the software was released. Hmmm, DNS issues, and various of other bugs perhaps?
I will be downloading from here: http://www.microsoft.com/en-us/download/details.aspx?id=39609 to introduce to my Exchange 2013 Server.
For more info check out the following TechNet Blog Post: http://blogs.technet.com/b/exchange/archive/2013/07/09/released-exchange-server-2013-rtm-cumulative-update-2.aspx