How to find objects in Active Directory with duplicate SMTP address.
- Run Active Directory Users and Computers.
- Right-click the domain object and choose Find from the context menu. This will bring up the Find Users, Contacts, and Groupswindow.
- In the Find drop-down list, choose Custom Search.
- Click the Advanced tab and in the Enter LDAP query: field, enter smtp alias, for eg:proxyaddresses=smtp:firstname.lastname@example.org
- Click the Find Now button.