I created a fresh setup of Zimbra 5.0.5 on a fresh installed Ubuntu 6.06 behind an ipcop firewall.
When receiving e-mails, the e-mail is received and virus checked fine. The next step the logfile shows is postfix/lmtp ... deferred ... connection refused. The reason is that the name resolution is done for the external IP address of my MX record.
Tests I did to check the configuration:
mail.xxx.com is configured in /etc/hosts as well as on the internal DNS server pointing to my internal IP address
My mail MX record points to mail.xxx.com: host -x mx xxx.com confirms mail.xxx.com
ping mail.xxx.com talks to my internal IP address
/etc/resolv.conf shows my internal DNS as the first DNS
Nevertheless the mail delivery catches the external IP address for my mail server rather the internal one. Any hints?