Search Active Directory for email accounts that are being forwarded elsewhere

I was asked by a member of the management team to shut off the email forwarding for all ex-employee accounts that were going to this particular person. Rather than go through all Active Directory user accounts to check whether forwarding was on or not, I did a quick online search and found an easy way to use an LDAP query to list only the accounts I needed to check. The original post is here

I'm still stuck with Exchange 2003, so here were the steps:

1. Open Active Directory Users and Computer
2. Right-click on your domain and choose Find
3. In the Find dropdown, change it to Custom Search
4. Go to the Advanced Tab
5. In the "Enter LDAP query" box, type (objectClass=*)(altrecipient=*) then click Find Now

The results will be all users that have email forwarding turned on. Please check the original post if you're looking for how to do this with Powershell in Exchange 2007. I'd guess it'll work the same in 2007 and newer versions