Create .csv files from all smtp email addresses in your (exchange 2003) environment.
csvde -f groups.csv -d "dc=home,dc=yourdomain,dc=local" -r "(&(objectClass=group)(mail=*))" -l "DN,displayName,proxyAddresses" csvde -f users.csv -d "dc=home,dc=yourdomain,dc=local" -r "(&(objectClass=user)(mail=*))" -l "DN,samAccountName,displayName,mail,proxyAddresses" csvde -f contacts.csv -d "dc=home,dc=yourdomain,dc=local" -r "(&(objectClass=contact)(mail=*))" -l "DN,displayName,targetAddress"