I want to setup a mail gateway using Zimbra. I intend to install Zimbra MTA for my testing but i don't find any option to route mail from mail gateway to mail host. I have read postfix document and found out "virtual_transport" option to config routing from mail gateway to mail host. I have tried to modify from "virtual_transport =error" to "virtual_transport=smtp:mailhost.domain.com:25 " but when i reload postfix, it return "virtual_transport=error".
Please help me.