When you install a new version of Exchange or apply a Cumulative Update certain AD attributes are updated to reflect the change. The updates are made in three different directory partitions (also known as naming contexts): Schema, Configuration and Domain. The following Microsoft TechNet article is a good reference for the different versions and the corresponding attribute values.
You can check the values manually….or you could do it the easy way with Powershell. Here’s a Powershell sample to give you values across the three partitions (assumes a single domain forest):
# Exchange Schema Version $sc = (Get-ADRootDSE).SchemaNamingContext $ob = "CN=ms-Exch-Schema-Version-Pt," + $sc (Get-ADObject $ob -pr rangeUpper).rangeUpper # Exchange Object Version (forest) $cc = (Get-ADRootDSE).ConfigurationNamingContext $fl = "(objectClass=msExchOrganizationContainer)" (Get-ADObject -LDAPFilter $fl -SearchBase $cc -pr objectVersion).objectVersion # Exchange Object Version (domain) - assumes single domain forest $dc = (Get-ADRootDSE).DefaultNamingContext $ob = "CN=Microsoft Exchange System Objects," + $dc (Get-ADObject $ob -pr objectVersion).objectVersion
The output will looking something similar to screenshot shown below (showing the values for Exchange Server 2013 CU5):