Postfix sending to A not MX

[Keith]

On 2/27/22 1:56 PM, Robert Heller wrote:
> At Sun, 27 Feb 2022 13:39:16 -0600 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>
>>
>> On 2/27/22 12:42 PM, Robert Heller wrote:
>>> At Sun, 27 Feb 2022 08:33:15 -0800 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>>>
>>>>
>>
>> [snip]
>>
>>
>>> It looks like you might not have a working DNS server.
>>>
>>
>> I'm a little surprised that postfix uses DNS at all given the following
>> line in the main.cf file:
>>
>> disable_dns_lookups                 = yes
>>
>> I don't run postfix, so maybe that setting does something other that the
>> more obvious interpretation of its name.
>
>  From postconf(5):
>
> disable_dns_lookups (default: no)
>         Disable DNS lookups in the Postfix SMTP and  LMTP  clients.  When
>         disabled,  hosts  are looked up with the getaddrinfo() system
>         library routine which normally also looks in /etc/hosts.
>
>         DNS lookups are enabled by default.
>
>
> Postfix *does need* to do a DNS lookup to find MX records...  If DNS lookups
> are disabled, I suspect Postfix can't do that, which is probably the OP's
> problem, if he in fact has that setting (and why would he have that setting
> for a Postfix server sending mail directly out to the Internet).  The only
> reason to turn this setting on would be for an Intranet ([Office] LAN only)
> mail server or one using a "smart host" (forwarding everthing to an uplink
> relay).
>
> I don't have that setting and am running with the default (no) on my mail
> server (running Postfix).
>
>

Well that's what I kinda thought, but I was a little confused given the
log output. Thanks for the verification.

I guess next step would be for OP to disable that setting (=no), restart
the daemon and see if that fixes the problem.

--
Keith