Virtual hosts are configured from the administration console Configure>Domains>Virtual Hosts page. The virtual host requires a valid DNS configuration with an A record.
When users log in, they enter the virtual host name in the browser. For example, https://mail.example.com. When the Zimbra logon screen displays, users enter only their user name and password. The authentication request searches for a domain with that virtual host name. When the virtual host is found, the authentication is completed against that domain.
