I have set up zimbra zcs-6.0.7_GA_2473.UBUNTU8_64.20100616212156 on my local LAN (domain.local). Zimbra server is running up fine for the local domain. Now i want to add an external domain (domain.com). Zimbra has a FQDN of mail.domain.local and is running behind a router with NAT set-up. I've added an MX record for domain.com which points to the router (mail.domain.com), on the router i've set up to forward 25 port to Zimbra (mail.domain.local). So what are the steps required on Zimbra to make it receive mail for domain.com and send all external mail using @domain.com addresses?