Can't connect to Mail Gateway externally on port 25

Oct 25, 2017
I have setup a 2 node cluster and have internal servers relaying though port 26 and it appears to be working properly. Internally in our network, I can connect to the cluster on ports 26 and 25. However, I would like to test incoming mail filtering and am not able to connect to the cluster on port 25 from external systems. I have verified that port 25 is open in the hardware firewall in front of the cluster.

I'm sure I'm missing something simple, but does anyone have any ideas what may be preventing external access to pot 25 in the cluster?


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