Re: Configuring Exim for mail delivery
On 2016-10-01, Brian <ad44@cityscape.co.uk> wrote:
> On Sat 01 Oct 2016 at 21:52:53 +0100, Liam O'Toole wrote:
>
>> On 2016-10-01, Brian <ad44@cityscape.co.uk> wrote:
>> > On Sat 01 Oct 2016 at 17:25:46 +0100, Liam O'Toole wrote:
>> >
>> >> On 2016-10-01, mo <mo777@gmx.net> wrote:
>> >> > First of all:
>> >> > Thank you Liam for your help! :)
>> >> > Thanks for the very nice and long explanation Mark! :)
>> >> >
>> >> > I think i should elaborate a little more on my setup.. i guess i did not
>> >> > make that very clear in the first place, sorry about that.
>> >> >
>> >> > My network is consisting of the following systems:
>> >> >
>> >> > Main PC - 192.168.23.11 (Running Debian Jessie)
>> >> > Server - 192.168.23.200 (Running Debian Jessie)
>> >> >
>> >> > The server is always online, the PC is only half of the day on.
>> >> >
>> >> > What i want to do now is the following:
>> >> >
>> >> > Sending mail from my Main PC to my Server and also the other way around,
>> >> > from the Server to my Main PC.
>> >> > The Server should also be able to send mail to the "outside" (Meaning to
>> >> > other SMTP servers).
>> >> > The second requirement is optional since i dont own a domain and all
>> >> > this is sitting locally at my home. The most important thing for me is
>> >> > to send and receive mail from both systems in my home network.
>> >> > I hope this made my problem a little clearer :)
>> >> >
>> >> > I'm a little ashamed to say that, but i could not totally follow your
>> >> > explanations Mark... I'm quite a newbie when it comes to SMTP.. sorry :(
>> >> >
>> >> > Thanks again for all your help ;)
>> >> >
>> >> > Greets
>> >> >
>> >> > mo
>> >> >
>> >> >
>> >>
>> >> I should have been a little clearer myself. You don't need to register a
>> >> domain name. Just invent your own domain name for local purposes. Let's
>> >> say you choose the domain name "monet", and that you have already given
>> >> the hostnames "desktop" and "server" to your two machines. Then you
>> >> would edit the file /etc/hosts on both machines to contain the following
>> >> lines:
>> >>
>> >> 192.168.23.11 desktop.monet desktop
>> >> 192.168.23.200 server.monet server
>> >
>> > I did that on gnome and desktop with appropriate changes:
>> >
>> > 192.168.7.20 desktop.monet desktop
>> > 192.168.7.67 gnome.monet gnome
>> >
>> >> Now you only need to tell exim4 on the server that it is the final
>> >> destination for emails to *.monet, again using the debconf wizard. You
>> >> will then be able to send emails to local addresses, while emails to all
>> >> other domains will go through your ISP's smarthost.
>> >
>> > I did that on gnome and desktop.
>> >
>> >> Incidently, you can also tell exim4 on the desktop to use the server as
>> >> its smarthost.
>> >>
>> >> I realise that you're getting lots of (sometimes contradictory)
>> >> information from various sources. The barebones configuration I have
>> >> described above has served me well for several years.
>> >
>> > All commands are issued from gnome.
>> >
>> > brian@gnome:~# ping -c3 desktop
>> > PING desktop.monet (192.168.7.20) 56(84) bytes of data.
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=1 ttl=64 time=0.267 ms
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=2 ttl=64 time=0.255 ms
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=3 ttl=64 time=0.269 ms
>> >
>> > --- desktop.monet ping statistics ---
>> > 3 packets transmitted, 3 received, 0% packet loss, time 2001ms
>> > rtt min/avg/max/mdev = 0.255/0.263/0.269/0.019 ms
>> >
>> > brian@gnome:~# ping -c3 desktop.monet
>> > PING desktop.monet (192.168.7.20) 56(84) bytes of data.
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=1 ttl=64 time=0.264 ms
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=2 ttl=64 time=0.255 ms
>> > 64 bytes from desktop.monet (192.168.7.20): icmp_seq=3 ttl=64 time=0.255 ms
>> >
>> > --- desktop.monet ping statistics ---
>> > 3 packets transmitted, 3 received, 0% packet loss, time 2002ms
>> > rtt min/avg/max/mdev = 0.255/0.258/0.264/0.004 ms
>> >
>> > We expect that result because ping uses files in /etc/nsswitch.
>> >
>> > root@gnome:~# exim -bt brian@desktop
>> > R: dnslookup for brian@desktop
>> > brian@desktop is undeliverable: Unrouteable address
>> >
>> > root@gnome:~# exim -bt brian@desktop.monet
>> > R: dnslookup for brian@desktop.monet
>> > brian@desktop.monet is undeliverable: Unrouteable address
>> >
>> > Am I the only one who gets this? No capability to deliver mail to
>> > desktop. What am I doing wrong?
>> >
>>
>> exim seems to be trying to resolve desktop.monet via DNS, thus ignoring
>> /etc/nsswitch. (I have no idea whether that is the default behaviour.) Do
>> you have a local DNS capable of resolving the address?
>
> Exim's default behaviour, as has been mentioned a couple of times in
> this thread, is to use DNS; nsswitch is not involved.
Doing an strace on the exim command shows that /etc/nsswitch is
consulted first, then /etc/resolv.conf (followed by a DNS lookup of the
smarthost).
> This is a default
> exim install; no files in conf.d altered. How about you?
No alterations I can remember, and 'dpkg --verify' reports no changes to
exim4-related files. All customisations have been done via debconf. I am
reluctant to divulge those customisations here, but I can tell you that
the settings are not particularly exotic. One host on the local network
is configured to use my ISP's SMTP server as its smarthost, while the
other hosts in turn use the former as their smarthost.
>> You might try the mail command from the mailutils or bsd-mailx packages
>> for comparison.
>
> mail uses exim as the MTA. It is hardly likely to work.
>
Indeed. Please strike my suggestion from the record, m'lud. I
misunderstood the meaning of the '-bt' switch you quoted above.
--
Liam
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