dabogdan

had a similar issue. I had to add dns forwarders to the firewall. Now it works. It used to for over a year or more without anything. strange

Peter. I have a single public IP which always makes matters interesting. That is why I'm using port forwarding for the email server. but yes, it's a 192.168.x.x subnet. An extra rule for the server and a no snat option fixed it. now the inbound emails show the source IP address. thanks again..

added an rule above the default rule for the email server only with no snat. that works perfectly. Thanks for the assistance!

turning off snat appears to drop all traffic

the email server is internal.