I'm running Zimbra 6.0.2 on Ubuntu 8.04 Server behind a firewall. The MX records are set correctly on a local DNS server, so that everything works fine for the primary domain MyDomain.com. Since I'm using this server as mail collector from two external accounts, I set up the Zimbra-internal fetchmail successfully. SMTP delivery is managed via smart host with SMTP auth. Everything works like a smooth - except the following:
I'm collecting mail from external account firstname.lastname@example.org - therefore I included the domain "domainb" in the domain section and set up the external account in the personal login. So I can send Mail from Zimbra via the SMTP smart host using the email@example.com address in the from field. Generally, this works as well, but when I try to send a mail from firstname.lastname@example.org to email@example.com, the MTA tries to deliver locally, and does not formward to the smart host, according to the logs.
Can anybody give me a hint on how to avoid this and make Zimbra deliver all mail for this secondary domains via smart host? Thanks in advance!