mail server and an outgoing mail server. This means that it must listen on
some port to receive email from the outside world ( this is port 25?, SMTP
). And it means that it must listen on some internal port, or scan some
local directories, for mail to send out to the outside world; how does this
work?
<ron's text>
So, if you want to send emails from box to box (and, of course,
internally) on your LAN, install an MTA on each machine. They
will have to be configured so that LAN traffic stays on the LAN
and internet mail is sent to your ISP's smtp server.
</ron's text>
I'm kind of confused as to why there would be a MTA on each machine. This
probably relates to the confusion related above though. Why couldn't I just
have the one machine with postfix, which exposed its services to the rest of
my machines?