Trying out the "new" feature (maybe it's been in for a while, and I never noticed it?) on the UTM to only listen on 1 select interface for SMTP. As soon as I click "custom" and add the interface the MX records point to (via Public IP/DNS) - SMTP breaks.
This still spits out in the log, but it doesn't appear to be listening, per external monitoring or testing.
no queue runs, listening for SMTP on port 25 (IPv4) port 587 (IPv4) and for SMTPS on port 465 (IPv4)
This thread was automatically locked due to age.