Unlike Windows operating system which clearly shows which service pack you have installed, it can be a bit tricker to keep tabs on which version of Exchange you are running.
For Exchange 2007, 2010, and 2013 you can use the Exchange Management Shell, with the following command:
Get-ExchangeServer | fl name, edition, admindisplayversion
Or you can use the Exchange Management Console, and click the Help menu, About Exchange Server 2010.
Now you know the version number you are running, check the post below to see which service pack/update rollup the version number refers to.
Exchange Server and Update Rollup Build Numbers
Related Articles:
1. How to install Exchange 2013 (SP1) on Windows Server 2012 R2
2. How to install Exchange 2010 (SP3) on Windows Server 2012
3. Exchange 2010 SP3 Update Rollup 7 released and installation tips
4. Exchange PowerShell: How to enumerate and modify Distribution Group properties
Great post !!
Here are some another ways to know the Exchange version from client and server side:
http://www.sysadmit.com/2015/07/exchange-saber-version-instalada.html