Hi, i have installed Zimbra on Ubuntu thanks to Howto Now i have 2 problems: 1 - If i have understand right Zimbra don't request mta/smtp user authentication when you send emails via smtp with a client in local network with Zimbra. es. zimbra server stmp ip 10.10.0.3 email client ip 10.0.0.2 Is this right? How can i force mta/stmp to authenticate a client in local network? I have seen that if you use a fake user with a fake domain you can however send emails... why? 2 - Zimbra use external dns servers also for delivery local mail? I don't have a dns server, for now, to add an A and a MX record for my test domain. There is a mode to tell zimbra to delivery local mail without a record mx? Thanks.