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Re: Mailma3 integrations
D?a 31. októbra 2021 13:33:41 UTC používate? Sherin A via Exim-users <exim-users@exim.org> napísal:

>   Everything on mailmal3 is ok , except exim is not delivering to
>mailman lmtp service on 127.0.0.1:8024  it is sending the following
>error log,
>
>1mhAnW-004vCv-It == my-list@domain.com R=mailman3_router
>T=mailman3_transport defer (-32) DT=0.000s: failed to lookup IP address
>for localhost

It seems, that your DNS is not translating localhost to IP, what is response to:

host localhost

(or dig, or nslookup, or any other DNS tool...)

You can try to use IP instead of localhost.
--
Slavko
Slavko

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Re: Mailma3 integrations [ In reply to ]
D?a 31. októbra 2021 13:33:41 UTC používate? Sherin A via Exim-users <exim-users@exim.org> napísal:

>   Everything on mailmal3 is ok , except exim is not delivering to
>mailman lmtp service on 127.0.0.1:8024  it is sending the following
>error log,
>
>1mhAnW-004vCv-It == my-list@domain.com R=mailman3_router
>T=mailman3_transport defer (-32) DT=0.000s: failed to lookup IP address
>for localhost

It seems, that your DNS is not translating localhost to IP, what is response to:

host localhost

(or dig, or nslookup, or any other DNS tool...)

You can try to use IP instead of localhost.
--
Slavko

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Re: Mailma3 integrations [ In reply to ]
Hello,

 The localhost usually don't have dns. It only have the ip entry in
/etc/hosts file which is not resolved by the resolver in
/etc/resolv.conf  . I changed  it to  Ip instead of localhost and exim
is delivering emails.

if we can setup a reverse look up exclude for host localhost , it will
be nice.

 Thank you for your help and support.



On 31/10/21 10:52 pm, Slavko (tblt) via Exim-users wrote:
> D?a 31. októbra 2021 13:33:41 UTC používate? Sherin A via Exim-users <exim-users@exim.org> napísal:
>
>>   Everything on mailmal3 is ok , except exim is not delivering to
>> mailman lmtp service on 127.0.0.1:8024  it is sending the following
>> error log,
>>
>> 1mhAnW-004vCv-It == my-list@domain.com R=mailman3_router
>> T=mailman3_transport defer (-32) DT=0.000s: failed to lookup IP address
>> for localhost
> It seems, that your DNS is not translating localhost to IP, what is response to:
>
> host localhost
>
> (or dig, or nslookup, or any other DNS tool...)
>
> You can try to use IP instead of localhost.

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Re: Mailma3 integrations [ In reply to ]
Hi,

D?a Sun, 31 Oct 2021 23:06:24 +0530 Sherin A via Exim-users
<exim-users@exim.org> napísal:

> if we can setup a reverse look up exclude for host localhost , it
> will be nice.

it seems, that you know very little about DNS:

host localhost
localhost has address 127.0.0.1
localhost has IPv6 address ::1

host 127.0.0.1
1.0.0.127.in-addr.arpa domain name pointer localhost.

host ::1
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa domain name pointer localhost.

I use three different DNS servers, two are serving localhost. The third
(my own) is not, but it responds only to TXT requests :-P

--
Slavko
https://www.slavino.sk
Re: Mailma3 integrations [ In reply to ]
It looks like you are not familiar with internet severs. I really don't
want to setup a local or intranet resolver and revese dns lookup server
for localhost.

The host command resolve from resolver not from localhost, as this sever
use public resolvers. See proof below,

root@u: ~ # host localhost
Host localhost not found: 3(NXDOMAIN)
root@u: ~ # dig localhost @8.8.8.8 +short
root@u: ~ # nslookup localhost
Server:        8.8.8.8
Address:    8.8.8.8#53

** server can't find localhost: NXDOMAIN

root@u: ~ # ping -t 3 localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.033 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.042 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.071 ms
64 bytes from localhost (127.0.0.1): icmp_seq=4 ttl=64 time=0.054 ms
64 bytes from localhost (127.0.0.1): icmp_seq=5 ttl=64 time=0.046 ms
64 bytes from localhost (127.0.0.1): icmp_seq=6 ttl=64 time=0.046 ms
64 bytes from localhost (127.0.0.1): icmp_seq=7 ttl=64 time=0.054 ms
64 bytes from localhost (127.0.0.1): icmp_seq=8 ttl=64 time=0.050 ms
^C
--- localhost ping statistics ---
8 packets transmitted, 8 received, 0% packet loss, time 7152ms
rtt min/avg/max/mdev = 0.033/0.049/0.071/0.010 ms
root@u: ~ # grep localhost /etc/hosts
127.0.0.1 localhost
::1     ip6-localhost ip6-loopback
root@u: ~ #

root@u: ~ # host 127.0.0.1
Host 1.0.0.127.in-addr.arpa. not found: 3(NXDOMAIN)
root@u: ~ #


On 31/10/21 11:49 pm, Slavko via Exim-users wrote:
> Hi,
>
> D?a Sun, 31 Oct 2021 23:06:24 +0530 Sherin A via Exim-users
> <exim-users@exim.org> napísal:
>
>> if we can setup a reverse look up exclude for host localhost , it
>> will be nice.
> it seems, that you know very little about DNS:
>
> host localhost
> localhost has address 127.0.0.1
> localhost has IPv6 address ::1
 This is because , your server solver or ISP have a DNS and RDNS for
localhost which resolve  fine
>
> host 127.0.0.1
> 1.0.0.127.in-addr.arpa domain name pointer localhost.
>
> host ::1
> 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa domain name pointer localhost.
>
> I use three different DNS servers, two are serving localhost. The third
> (my own) is not, but it responds only to TXT requests :-P
Yes, as  I said my resolvers don't have the RDNS / DNS for localhost
>
>
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Re: Mailma3 integrations [ In reply to ]
On 2021-10-31 at 13:36:24 UTC-0400 (Sun, 31 Oct 2021 23:06:24 +0530)
Sherin A via Exim-users <sherinmon@gmail.com>
is rumored to have said:

> Hello,
>
>  The localhost usually don't have dns. It only have the ip entry in /etc/hosts file which is not resolved by the resolver in /etc/resolv.conf  . I changed  it to  Ip instead of localhost and exim is delivering emails.
>
> if we can setup a reverse look up exclude for host localhost , it will be nice.

That should never be needed. If your system name resolution config (i.e. traditionally nsswitch.conf, /etc/hosts, and /etc/resolv.conf) does not let you resolve 'localhost' to 127.0.0.1 and/or ::1 (with symmetric reverse lookups) then you have a broken system name resolution config.

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Re: Mailma3 integrations [ In reply to ]
Hi,

D?a 31. októbra 2021 18:31:59 UTC používate? Sherin A via Exim-users <exim-users@exim.org> napísal:
>It looks like you are not familiar with internet severs. I really don't
>want to setup a local or intranet resolver and revese dns lookup server
>for localhost.

The best practice for MTA is to have own recursive (and caching) DNS server, especially
(but not limited to) when you use DNS RBL lists. And when you use own DNS server, you
should be aware of RFC 1912, which says in 4.1 section:

Certain zones should always be present in nameserver configurations (beside other):

localhost
0.0.127.in-addr.arpa

...

The "localhost" address is a "special" address which always refers to the local host. It
should contain the following line:

localhost. IN A 127.0.0.1

...and relevant PTR for it.

(note the dot after localhost)

RFC doesn't tell MUST, only SHOULD, thus one do not need to have it, but having it prevents
its leak to upstream servers. And, when you do not have it, you cannot expect, that it will be
resolved by DNS query, what was clearly shown in your log line.

>root@u: ~ # dig localhost @8.8.8.8 +short
>root@u: ~ # nslookup localhost
>Server:        8.8.8.8
>Address:    8.8.8.8#53

Do not use google as ethalon, it is machine to make money, nothing less, nothing more...
Slavko

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