Schema Version

Schema Version:-
Windows 2000 :13
Windows 2003 :30
Windows 2003 R2:31
Windows 2008 :44
Windows 2008R2 :47
Windows Server 2012 : 56
Windows Server 2012 R2 : 69

We can see the schema version from adsiedit.msc.The attribute is "object version".

Or you can use dsquery
dsquery * cn=schema,cn=configuration,dc=domainname,dc=local -scope base -attr objectVersion


Verify ForestPrep, Domainprep & Rodcprep Result -
Powershell & DSQuery

http://social.technet.microsoft.com/wiki/contents/articles/23219.verify-forestprep-domainprep-rodcprep-result.aspx

How to find users logon name by their mail address for bulk users?

For Single user
dsquery * domainroot -filter "(&(objectCategory=Person)(objectClass=User)(mail=e-mailaddress))" -attr name

For bulk users
for /f %%x in (%1) do dsquery * domainroot -filter "(&(objectcategory=person)(objectclass=user)(mail=%%x))" -attr name