I have noticed that at the zimbra admin UI. There is two settings to set hostname one at the servers menu at MTA tab the Web mail MTA Hostname is set to my real server hostname. While at global settings at MTA tab the Web mail MTA Hostname is set to local host. My server sends and recieves mail from internet but i have problem that sometimed it's listed in CBL and mail servers block my emails such as aol and hotmail and wsu.edu. So, Can that be the problem. Should i change the hostname in global settings to my real server hostname also?