mail to another machine on the LAN

[Tim]

On Wed, 2010-10-27 at 14:20 +0400, Hiisi wrote:
> Now I'm able to telnet to 192.168.3.30 on port 25 and can leave a mail
> for user on that machine. However it's still impossible to send mail
> to <user>@192.168.3.30 from router. The message is returned with error
> (reason: 550 Host unknown). It's name resolution problem, right? What
> should I change and on which machine to solve it? And once more time
> about my configuration: I don't worry about intrusion on the the LAN.
> There's nobody except me and my brother. I think I can even turn off
> SELinux and iptables on that machine. It will receive messages only
> from router.

When I tried to get my modem/router to email its logs to a computer in
my LAN, and went through similar problems.  The router would try to use
the DNS servers it knew about (the ones the ISP sets up through DHCP),
and obviously they couldn't resolve my LAN addresses.  But, I gather
from your first message that your router is a computer, not a device, so
your problem ought to be different.

I think you want to check that each computer in the equation can resolve
its own name, and the other computer's.  Avoid using "localhost" as part
of the mail addresses.

On my LAN, I have a DNS server that all the computers use, and it has
all the local machine names in its records.  It solved a lot of name
issues, and freed me from ever having to mess around with hosts files,
again.

The [bracketing] the IP address after the @ sign ought to work, to use
an IP address without name lookups, but I don't know if everything does
that trick.

Where are you seeing the error messages?  The SMTP server logs from
where you're trying to send from, trying to receive at, or something
else?

Later on you mention a "user unknown" error.  Are you accidentally
trying to send mail out using your ISP's SMTP server?

-- 
[tim at localhost ~]$ uname -r
2.6.27.25-78.2.56.fc9.i686

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