On Wed, 20 Sep 2017 05:45:07 -0400,
Bas Zoutendijk wrote:
>
> Dear Gentoo Users,
>
> On my new Gentoo laptop installation I recently installed Sendmail in
> order to receive messages from Cron on the root account. I noticed that
> when I connect my laptop to a different network than the one I connected
> to during booting, Sendmail does not know what to do with the Cron mail
> any more.
>
> For the purpose of clarity, let’s say the host name of this laptop is
> ‘hostname’. I did not configure the domain part of the host name
> because of the mobile nature of this machine.
>
> When I boot at home, Cron sends mail to root@hostname.homedomain.
> ‘homedomain’ is automatically added to all host names on my home network
> by the router. It can only be resolved inside the network; it is not a
> registered domain name. I can receive mail from Cron just fine.
>
> When I boot at work, Cron sends mail to root@hostname. Note that the
> domain name ‘workdomain’ is not added to the host name. I can still
> receive Cron mail. However, when I take the laptop home without
> rebooting and connect to the home network, Sendmail is unable to deliver
> the Cron mail for root@hostname.homedomain and sends notifications of
> this to root@hostname.homedomain, which somehow do seem to arrive
> without problems. The error message is “config error: mail loops back
> to me”.
>
> Based on what I can find about this error on the internet, it looks like
> Sendmail does not know where hostname.homedomain is and asks my router
> to resolve that. When it finds out it is localhost, it thinks something
> is wrong and does not deliver the mail. A possible solution is to
> register hostname.homedomain as an alias of hostname or localhost, but I
> would rather not do that, since hard coding domain names on a laptop
> seems kludgy to me.
>
> Does anyone know a more elegant solution? Some way to inform Sendmail
> about changes to the domain name, or configure it to check for these
> changes? I would rather not have to reboot. Restarting Sendmail is
> acceptable, I guess, but perhaps not the most elegant solution.
Restarting sendmail seems fine with me, if you want to have something
that works everywhere, why not get a domain name from ddns or
somewhere and use a full fqdn all the time -- you can put your home
machine on another host in that domain and you will be good to go.
--
Your life is like a penny. You're going to lose it. The question is:
How do
you spend it?
John Covici
cov...@ccs.covici.com
