We've just installed Zimbra Appliance Edition, and we can access to web client to manage it. We'll migrate exchange.
But, Before migrating to Exchange, we want to send and receive emails in Zimbra environment as well, (clean environment), but we can't.

I don't know if we have to do any special configuration.
But we can't recieve any message in our mailboxes.

Actions Taken:

• DNS is configured correctly, It resolves our domain
• It recognizes AD users, but it doesn't let us download their mailboxes.
• It doesn't receive emails created with zimbra users, but it says email was sent successfully
• MX records have been already checked
• No problems with external IP's and FireWall.