
Open the Active Directory Users and Computers tool from Control Panel \ Administrative tools or running below command from Start > Run...
dsa.msc
Under Active Directory Users and Computers, Right click on the domain and click on Find
In the find window click on the Find choice and pick Custom Search; Click on the Advanced tab; Enter in the LDAP Query that follows this syntax:
(proxyAddresses=SMTP:User@domain)
Make...