Sending LMTP to localhost

[Mitch]

I've got a NAT firewall setup. I don't want to poke a hole for 7025 on the external address so I need postfix to talk to 7025 on either the internal address or localhost. I tried disabling Enable DNS lookups and adding my mail server host as 127.0.0.1 in /etc/hosts. However, now when I try to email an external domain is tries contact the IP of the server's A record rather than the MX record. What am I doing wrong?

Thanks,
Mitch

[brian]

You can force jetty to bind to a specific address by setting zimbraLmtpBindAddress on the server config.

The real problem is that provisioning new accounts will set zimbraMailTransport attribute on the account to something like lmtp:server.domain.tld:7025 where server.domain.tld is taken from the zimbraMailHost attribute and 7025 is taken from zimbraLmtpBindPort of the server.

Setting zimbraLmtpBindAddress will not change the default behaviour of zimbraMailTransport when provisioning new users.

[Mitch]

Yuck. I read about the split DNS workaround. I'll try that.

Thanks,
Mitch

[Mitch]

I found the most painless solution was to use iptables:

iptables -t nat -A OUTPUT -p tcp -d EXTERNAL_IP --dport 7025 -j DNAT --to INTERNAL_IP