Search AD for email aliases
There's no gui tool to easily find an email aliases in Active Directory
Found this and it works!
- Open AD and right click 'find' on the domain
- Custom Search
- Advanced tab and choose LDAP Query
- Add the following line to the field: proxyaddresses=smtp:firstname.lastname@example.org
- you can you use wildcards which is helpful - especially if you host multiple domains (something*@*.com) will yield results :)