Is Port25 blocked?

[WhiteTiger]

A server in DMZ sends error messages to an external email address.
The server that should receive them rejects them on port 25.
From a first check it would seem that the ISP does not block port 25 on incoming, but only on outgoing.

While waiting for their confirmation, I wonder if it is OPNsense+Zenarmor blocking it.

WAN, LAN, DMZ networks do not have my own blocking rules. On the contrary, there is still a Protocol Any / Ports Any / Sources Any / Destinations Any rule.

[sy]

Hi,

What about Zenarmor block reports? Do you see any block record in Live sessions - Blocks?