On Wed, Jan 05, 2022 at 11:03:02AM -0500, Sean McBride wrote: > pass in log quick on egress proto tcp to any port smtp
> If on the OpenBSD system itself I do `telnet > localhost 25` I see the built-in OpenSTMPD. But if I telnet from another > machine on my LAN, I fail to connect. Shouldn't that rule have opened port > 25? Assuming that you only have a single network card and that it is configured with the default routes, then yes, that rule will open port 25 to the other machines on your LAN. Have you actually changed the default /etc/mail/smtpd.conf to listen for external connections? By default it only listens on the loopback interface, (and local socket).