I set tehm like this when we installed our zimbra server
Code:
Set objParent = GetObject("LDAP://OU=Year CC,DC=College,DC=internal")
objparent.Filter = Array("user")
for each objUser in objParent
'Wscript.Echo "Modifying " & objUser.Get("sAMAccountName")
objUser.put "mail", objUser.Get("sAMAccountName") & "@email.address"
objuser.put "targetAddress","SMTP:" & objUser.Get("sAMAccountName") & "@email.address"
objuser.put "proxyAddresses", "SMTP:" & objUser.Get("sAMAccountName") & "@email.address"
objuser.put "mailNickname", objUser.Get("sAMAccountName")
objuser.Setinfo
next
Wscript.Echo "Done ;)" then ran it on each OU