I don't want that users can sent mail with port 25 configured in outlook. When I configure port 587 and verification is required in Outlook, everything is ok.. But when I disable verification and choose port 25, it's also ok... But i don't want that... Verification have to be required and only with port 587, is that possible with Zimbra server?
SOLVED:When you are in local network you can sent with port 25... From outside, it doesn't work, so it's ok.. MTA Trusted Networks is important here..