Finding email addresses on an object in Active Directory

You can find a duplicate email address, by using Active Directory Users and Computers, then following this procedure:

To search for a duplicate address do the following:

1. Open Active Directory Users and Computers.
2. Right click on your domain name and click on the “find” option.
3. Then choose “custom search”.
4. Then click on the “Advanced” tab.
5. Under “Enter LDAP query:” type the next search query.
6. proxyaddresses=smtp:useremail@domain.com
7. Click find you you should find all objects with the duplicate address.