Subject: sendmail domain configuration as Message 9

[John Wong]

Hi Allen,
 
I believe you need to ask your ISP to add a DNS MX record for system.house.network.
 
Why don't you just change house.network to one of your registered domain? The reason it work is because BigDaddy.com created DNS MX records for those domains.
 
Hope it will help.
 
jw

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Message: 9
Date: Thu, 26 Aug 2010 19:01:16 -0400
From: "Allen, Jack" <Jack.Allen at mckesson.com>
To: General Red Hat Linux discussion list <redhat-list at redhat.com>
Subject: sendmail domain configuration
Message-ID:
    <230ED15F81AFD3409345FFA4E565F0E50D2B4FB1 at NDHV3000.na.corp.mckesson.com>
    
Content-Type: text/plain;    charset="us-ascii"

Hello:

        I need to know exactly what options need to be specified in
sendmail.mc to generate the proper sendmail.cf file so the domain name
my ISP sees is valid.

        Here is some information why this is needed. I have 2 Windows PC
and 1 Linux systems and several Home Automation, NAS, Media systems on a
home network. I have named running on the Linux system for a local
fictional domain called "house.network". I know network is longer than
the normal 3 character .com, .net, ..., but it works with no problems as
far as name lookup and what have you. I also chose the longer name so
there would be no conflict with a real domain name out in the real world
and thing on my local network would not get routed to it. I have some of
the special systems send email to the Linux system which then has
aliases to send certain emails to my ISP email and/or my work email.
This is where the problem starts.

        If the Linux host name is set to system. house.network, then
when it connects to the ISP I get error 550 Invalid sender domain. This
is because the domain cannot be looked up by the ISP and I can
understand why. If I set the Linux host name to system.my_domain.net it
works like it should. I registered 2 real domain names (my_domain.com
and my_domain.net) with BigDaddy.com partly for this. But when the Linux
host name is not in the same domain as the other systems on my local
network it cause some other problem.

        If I add the option in sendmail.mc to generate a sendmail.cf
file with Djmy_domain.net and have the Linux host name set to
system.house.network the ISP complains with basically the same 550
error. Looking at the returned email some of the header information
looks like:

Reporting-MTA: dns; my_domain.net

Received-From-MTA: DNS; system.house.network

Which indicates to me the value of the host name is what my ISP sees
that it tries to validate. I have looked at and tried various
configurations for masquerading, but have the same problem. It seems to
rewrite certain header entries that basically the user's client software
look at to display from and to and what have you, but does not change
the Received-From-MTA entry.

        So I hope someone has some good suggestions to help me resolve
this problem.

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Jack Allen