I have installed Zimbra Open source on RHEL5.2. This is a fantastic mail server no doubt about it anybody can install it and use it. Now my main purpose of zimbra mail server is use as a internal mail server, in our office approximate 75 users are using Outlook for Send/Receive mails. Our mail server is hosted at One of ISP. I have configure DNS in Linux and zimbra mail server with same name of company name which is hosted at ISP with same name, for example (anand.in at ISP and anand.in at our office means internal mail server). Now my problem is our 25 users are using Laptops and they are mostly travels for business. They are using data card for send/receive their mails, I have created dummy accounts in internal mail server, If I send the mail their accounts the mails are going is internal mail server i.e. In dummy accounts not in hosted mail accounts. In the Zimbra mail server Our MTA setting is “Web mail MTA Hostname = Internal mail server IP Addess” and
“ Relay MTA for external delivery = ISP Server IP Address ”.
Kindly suggest How to resolve this issue. Appreciate your help.