You can easily get the Exchange version for all Exchange servers in your domain with this one-liner. Run it from an Exchange Management Shell.
Get-ExchangeServer | Select Name,AdminDisplayVersion,Edition,ServerRole
The following information is displayed:
|Name :||the server name|
the version and build of the server
You can cross-reference this with the Exchange version matrix to find out which updates are installed.
|Edition :||can be Standard or Enterprise|
|ServerRole :||the roles on the server specified by Name|