Quote:
Originally Posted by csoliss  this is my firewall configuration
port 25 Protocol: SMTP
incoming: from any to 192.0.0.121(zimbra server IP) 192.0.0.151 (other mail server)
outcoming from any to any
NOTE: the other mail server have other domain. |
You may have done this but not fully explained it here, I don't know. What I see missing from your config descriptions is that you must have a different published PUBLIC ip address for each of your mail servers (since there are two) and for each, you have to have a Destination Network Address Translation (DNAT) rule that accepts traffic from
to the public ip and translates its destination to the appropriate private IP.
Then, if you ever want to do externally-authenticated users, you also need an SNAT (Source NAT) rule that takes outgoing traffic from your Zimbra server and translates its source to the public IP of your mailserver; otherwise it'll be sourced as the primary IP of your firewall which will result in RDNS lookup failures and failure to authenticate for external clients.